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Full vulnerability report · 2026
CVE-2026-94127High confidence

F5 BIG-IP APM Heap-based Buffer Overflow Vulnerability

F5 · BIG-IP APM

Official source article: F5 K000162605 ↗. Check the applicable product and release in the original source.

9.3CriticalCVSS 4.0
Recommended action
Patch now

CISA confirms exploitation in the wild and lists 2026-09-25 as the remediation due date.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityCriticalOperational priority:Critical, unchanged from published severity.unchanged

Evidence used

  • CISA confirms exploitation in the wild.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 2.23% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs F5 BIG-IP APM and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-84427

EU known exploited

When a BIG-IP APM access policy and an OAuth profile are configured on a virtual server, specific malicious traffic can lead to remote code execution (RCE). This vulnerability is only present when BIG-IP APM is configured as an OAuth Authorization Server. Deployments using APM strictly as an OAuth Client / Resource Server (without OAuth authorization server profiles configured) are not affected by this vulnerability. Impact: This vulnerability allows an unauthenticated attacker to perform remote code execution. The BIG-IP system in Appliance mode is also vulnerable. This is a data plane issue; there is no control plane exposure. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 22 Sep 2026. Evidence sources: cisa_kev, eukev_kev.
ENISA score
9.3 · CVSS 4.0
Advisory evidence
1 linked advisory record
Explicit mitigation evidence

Only statements that explicitly mention a fix, patch, update, workaround or mitigation are shown here.

  • csaf_ncscnl · NCSC-2026-0386Kwetsbaarheid verholpen in F5 Networks BIG-IP Access Policy Manager
Recommended actionPatch now

CISA confirms exploitation in the wild and lists 2026-09-25 as the remediation due date.

Patch available
01

What, why and how

F5 BIG-IP APM contains a heap-based buffer overflow vulnerability when access policy and an OAuth profile are configured on a virtual server. This vulnerability could allow an unauthenticated attacker to perform remote code execution.

What

F5 BIG-IP APM contains a heap-based buffer overflow vulnerability when access policy and an OAuth profile are configured on a virtual server. This vulnerability could allow an unauthenticated attacker to perform remote code execution.

Why

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

What

F5 BIG-IP APM contains a heap-based buffer overflow vulnerability when access policy and an OAuth profile are configured on a virtual server. This vulnerability could allow an unauthenticated attacker to perform remote code execution.

Why

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2026-09-22.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Heap-based Buffer Overflow → execute code or commands in the affected security context
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-122 ↗

CWE-122: Heap-based Buffer Overflow. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkUnauthenticatedRemote code executionCWE-122CISA KEV
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-84427Known-exploited evidence recorded

When a BIG-IP APM access policy and an OAuth profile are configured on a virtual server, specific malicious traffic can lead to remote code execution (RCE). This vulnerability is only present when BIG-IP APM is configured as an OAuth Authorization Server. Deployments using APM strictly as an OAuth Client / Resource Server (without OAuth authorization server profiles configured) are not affected by this vulnerability. Impact: This vulnerability allows an unauthenticated attacker to perform remote code execution. The BIG-IP system in Appliance mode is also vulnerable. This is a data plane issue; there is no control plane exposure. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Official EUVD record ↗
BSI · German · WID-SEC-2026-3517F5 BIG-IP APM: Schwachstelle ermöglicht Codeausführung

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in F5 BIG-IP APM ausnutzen, um beliebigen Programmcode auszuführen.

Official advisory ↗
Canadian Centre for Cyber Security · English · AV26-949F5 security advisory (AV26-949) - Update 1

As of September 22, 2026, F5 is affected by a vulnerability in the following product: F5 has reported that CVE-2026-94127 is being exploited in the wild.

Official advisory ↗
Canadian Centre for Cyber Security · English · AL26-022AL26-022 - Vulnerability impacting F5 BIG-IP Access Policy Manager (APM) – CVE-2026-94127

An Alert is used to raise awareness of a recently identified cyber threat that may impact cyber information assets, and to provide additional detection and mitigation advice to recipients. The Canadian Centre for Cyber Security ("Cyber Centre") is also available to provide additional assistance regarding the content of this Alert to recipients as requested.

Official advisory ↗
INCIBE-CERT · Spanish · desbordamiento-de-bufer-basado-en-monticulo-en-big-ip-apm-de-f5Desbordamiento de búfer basado en montículo en BIG-IP APM de F5

F5 ha publicado una vulnerabilidad de severidad crítica que, en caso de ser explotada, podría permitir a un atacante remoto no autenticado ejecutar código arbitrario y comprometer por completo el dispositivo afectado. F5 ha confirmado la explotación activa de esta vulnerabilidad.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1220Vulnérabilité dans F5 BIG-IP

Une vulnérabilité a été découverte dans F5 BIG-IP. Elle permet à un attaquant de provoquer une exécution de code arbitraire à distance. L'éditeur indique que la vulnérabilité CVE-2026-94127 est activement exploitée. Des indicateurs de compromission sont disponibles dans l'avis de l'éditeur.

Official advisory ↗
NBSZ-NKI · Hungarian · cve-2026-94127CVE-2026-94127

A halom túlcsordulás egy típusú puffer túlcsordulás, ahol a felülírható puffer a memória dinamikusan részében van kiosztva, ami általában azt jelenti, hogy a puffert egy olyan függvénnyel osztották ki, mint pl. a malloc().

Official advisory ↗
CSIRT Italia · Italian · f5-big-ip-rilevato-sfruttamento-in-rete-della-cve-2026-94127F5 BIG-IP: rilevato sfruttamento in rete della CVE-2026-94127

Nel dettaglio, la vulnerabilità identificata tramite la CVE-2026-94127 - di tipo “ Remote Code Execution ” e con score CVSS v3.1 pari a 9.8 – riguarda la componente OAuth di BIG-IP APM, che sarebbe soggetta a un possibile buffer overflow . Un attaccante remoto non autenticato, tramite richieste opportunamente predisposte, potrebbe sfruttare tale vulnerabilità per eseguire codice arbitrario sui sistemi interessati.

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6965美 CISA 발표 주요 Exploit 정보공유(Update. 2026-09-22)

F5 BIG-IP APM Heap-based Buffer Overflow Vulnerability

Official advisory ↗
NCSC-NL · Dutch · NCSC-2026-0386Kwetsbaarheid verholpen in F5 Networks BIG-IP Access Policy Manager

F5 BIG-IP APM contains a heap-based buffer overflow vulnerability in OAuth Authorization Server configurations that can lead to unauthenticated remote code execution when processing specific malicious traffic.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
BIG-IP: 17.5.0 < Hotfix-BIGIP-17.5.1.9.0.160.12-ENG, 17.1.0 < Hotfix-BIGIP-17.1.3.5.0.41.14-ENG, 21.1.0 < Hotfix-BIGIP-21.1.0.2.0.30.22-ENG
Fixed
The Cyber Centre strongly recommends that organizations running affected F5 BIG‑IP APM deployments upgrade to the following vendor-supported fixed hotfix releases: Affected product Affected versions Fixed Versions BIG IP APM Versions 17.1.0 prior to Hotfix-BIGIP-17.1.3.5.0.41.14-ENG Version 17.1.0 Hotfix-BIGIP-17.1.3.5.0.41.14-ENG BIG IP APM Versions 17.5.0 prior to Hotfix-BIGIP-17.5.1.9.0.160.12-ENG Version 17.5.0 Hotfix-BIGIP-17.5.1.9.0.160.12-ENG BIG IP APM Versions 21.1.0 prior to Hotfix-BIGIP-21.1.0.2.0.30.22-ENG Version 21.1.0 Hotfix-BIGIP-21.1.0.2.0.30.22-ENG The Cyber Centre also recommends organizations to: Identify vulnerable BIG IP systems that have both an APM access policy and an OAuth profile configured on a virtual server. Apply the vendor-provided iRule (contact F5 Support to obtain the iRule) Footnote 1 . Review access logs for indicators of compromise (IoC), particularly OAuth authentication failures especially in rapid succession or large volume Footnote 1 . Also review administrative accounts, access policies for any signs of suspicious activity. Upgrade to a vendor-supported fixed software version as soon as possible. Ensure management interfaces are restricted to trusted administrative networks. Follow F5 guidance for vulnerability remediation and validation following patch deployment. Note: Organizations operating Common Criteria Footnote 5 evaluated configurations should review F5's advisory Footnote 1 and apply the recommended updates in accordance with their change management and certification requirements. In addition, the Cyber Centre strongly recommends that organizations review and implement the Cyber Centre’s Top 10 IT Security Actions Footnote 6 with an emphasis on the following topics: Consolidating, monitoring, and defending Internet gateways Patch operating systems and applications Harden operating systems and applications Isolate web-facing applications Should activity matching the content of this alert be discovered, recipients are encouraged to report via My Cyber Portal , or email contact@cyber.gc.ca .
Action
Apply the fixed release for the affected product branch as recorded by Canadian Centre for Cyber Security. Validate the exact product and build in the linked advisory before deployment.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 22 Sept 2026 · Last source change 23 Sept 2026, 03:55 UTC · CWE-122 · Heap-based Buffer Overflow

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-23
European sourceENISA EUVD · EUVD-2026-84427
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. BlackTree coverageBlackTree article coverage changed from no BlackTree article to 1 BlackTree article.
    Before
    no BlackTree article
    After
    1 BlackTree article
    BlackTree editorial ↗
  2. ENISA known-exploited stateENISA EUVD now records this CVE in its known-exploited dataset.
    Before
    not listed in ENISA EUVD known-exploited dataset
    After
    listed in ENISA EUVD known-exploited dataset (EUVD-2026-84427)
    ENISA EUVD ↗
  3. ENISA EUVD mappingEUVD-2026-84427 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-84427"}
    ENISA EUVD ↗
  4. Vendor guidanceAuthoritative vendor guidance changed: removed remediation: cyber.gc.ca/al26-022-vulnerability-impacting-f5-big-ip-access-policy-manager-apm-cve-2026-94127.
    Before
    remediation: cyber.gc.ca/al26-022-vulnerability-impacting-f5-big-ip-access-policy-manager-apm-cve-2026-94127 · vendor advisory: my.f5.com/K000162605
    After
    vendor advisory: my.f5.com/K000162605
    f5sirt@f5.com ↗
  5. Remediation statusRemediation status changed from Patch available to Awaiting fix.
    Before
    Patch available
    After
    Awaiting fix
    f5sirt@f5.com ↗
  6. Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: my.f5.com/K000162605.
    Before
    no authoritative guidance recorded
    After
    vendor advisory: my.f5.com/K000162605
    f5sirt@f5.com ↗
  7. Vendor guidanceAuthoritative vendor guidance changed: removed remediation: cyber.gc.ca/al26-022-vulnerability-impacting-f5-big-ip-access-policy-manager-apm-cve-2026-94127.
    Before
    remediation: cyber.gc.ca/al26-022-vulnerability-impacting-f5-big-ip-access-policy-manager-apm-cve-2026-94127
    After
    no authoritative guidance recorded
    CISA KEV ↗
  8. Affected versionsThe structured affected or fixed version information changed.
    Before
    BIG-IP: 21.1.0 < Hotfix-BIGIP-21.1.0.2.0.30.22-ENG, 17.5.0 < Hotfix-BIGIP-17.5.1.9.0.160.12-ENG, 17.1.0 < Hotfix-BIGIP-17.1.3.5.0.41.14-ENG · Fixed: The Cyber Centre strongly recommends that organizations running affected F5 BIG‑IP APM deployments upgrade to the following vendor-supported fixed hotfix releases: Affected product Affected versions Fixed Versions BIG IP APM Versions 17.1.0 prior to Hotfix-BIGIP-17.1.3.5.0.41.14-ENG Version 17.1.0 Hotfix-BIGIP-17.1.3.5.0.41.14-ENG BIG IP APM Versions 17.5.0 prior to Hotfix-BIGIP-17.5.1.9.0.160.12-ENG Version 17.5.0 Hotfix-BIGIP-17.5.1.9.0.160.12-ENG BIG IP APM Versions 21.1.0 prior to Hotfix-BIGIP-21.1.0.2.0.30.22-ENG Version 21.1.0 Hotfix-BIGIP-21.1.0.2.0.30.22-ENG The Cyber Centre also recommends organizations to: Identify vulnerable BIG IP systems that have both an APM access policy and an OAuth profile configured on a virtual server. Apply the vendor-provided iRule (contact F5 Support to obtain the iRule) Footnote 1 . Review access logs for indicators of compromise (IoC), particularly OAuth authentication failures especially in rapid succession or large volume Footnote 1 . Also review administrative accounts, access policies for any signs of suspicious activity. Upgrade to a vendor-supported fixed software version as soon as possible. Ensure management interfaces are restricted to trusted administrative networks. Follow F5 guidance for vulnerability remediation and validation following patch deployment. Note: Organizations operating Common Criteria Footnote 5 evaluated configurations should review F5's advisory Footnote 1 and apply the recommended updates in accordance with their change management and certification requirements. In addition, the Cyber Centre strongly recommends that organizations review and implement the Cyber Centre’s Top 10 IT Security Actions Footnote 6 with an emphasis on the following topics: Consolidating, monitoring, and defending Internet gateways Patch operating systems and applications Harden operating systems and applications Isolate web-facing applications Should activity matching the content of this alert be discovered, recipients are encouraged to report via My Cyber Portal , or email contact@cyber.gc.ca .
    After
    BIG-IP: 21.1.0 < Hotfix-BIGIP-21.1.0.2.0.30.22-ENG, 17.5.0 < Hotfix-BIGIP-17.5.1.9.0.160.12-ENG, 17.1.0 < Hotfix-BIGIP-17.1.3.5.0.41.14-ENG · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CISA KEV ↗
  9. Remediation statusRemediation status changed from Patch available to Awaiting fix.
    Before
    Patch available
    After
    Awaiting fix
    CISA KEV ↗
  10. Vendor guidanceAuthoritative vendor guidance changed: removed remediation: cyber.gc.ca/al26-022-vulnerability-impacting-f5-big-ip-access-policy-manager-apm-cve-2026-94127.
    Before
    remediation: cyber.gc.ca/al26-022-vulnerability-impacting-f5-big-ip-access-policy-manager-apm-cve-2026-94127
    After
    no authoritative guidance recorded
    CISA KEV ↗
  11. Affected versionsThe structured affected or fixed version information changed.
    Before
    BIG-IP: 21.1.0 < Hotfix-BIGIP-21.1.0.2.0.30.22-ENG, 17.5.0 < Hotfix-BIGIP-17.5.1.9.0.160.12-ENG, 17.1.0 < Hotfix-BIGIP-17.1.3.5.0.41.14-ENG · Fixed: The Cyber Centre strongly recommends that organizations running affected F5 BIG‑IP APM deployments upgrade to the following vendor-supported fixed hotfix releases: Affected product Affected versions Fixed Versions BIG IP APM Versions 17.1.0 prior to Hotfix-BIGIP-17.1.3.5.0.41.14-ENG Version 17.1.0 Hotfix-BIGIP-17.1.3.5.0.41.14-ENG BIG IP APM Versions 17.5.0 prior to Hotfix-BIGIP-17.5.1.9.0.160.12-ENG Version 17.5.0 Hotfix-BIGIP-17.5.1.9.0.160.12-ENG BIG IP APM Versions 21.1.0 prior to Hotfix-BIGIP-21.1.0.2.0.30.22-ENG Version 21.1.0 Hotfix-BIGIP-21.1.0.2.0.30.22-ENG The Cyber Centre also recommends organizations to: Identify vulnerable BIG IP systems that have both an APM access policy and an OAuth profile configured on a virtual server. Apply the vendor-provided iRule (contact F5 Support to obtain the iRule) Footnote 1 . Review access logs for indicators of compromise (IoC), particularly OAuth authentication failures especially in rapid succession or large volume Footnote 1 . Also review administrative accounts, access policies for any signs of suspicious activity. Upgrade to a vendor-supported fixed software version as soon as possible. Ensure management interfaces are restricted to trusted administrative networks. Follow F5 guidance for vulnerability remediation and validation following patch deployment. Note: Organizations operating Common Criteria Footnote 5 evaluated configurations should review F5's advisory Footnote 1 and apply the recommended updates in accordance with their change management and certification requirements. In addition, the Cyber Centre strongly recommends that organizations review and implement the Cyber Centre’s Top 10 IT Security Actions Footnote 6 with an emphasis on the following topics: Consolidating, monitoring, and defending Internet gateways Patch operating systems and applications Harden operating systems and applications Isolate web-facing applications Should activity matching the content of this alert be discovered, recipients are encouraged to report via My Cyber Portal , or email contact@cyber.gc.ca .
    After
    BIG-IP: 21.1.0 < Hotfix-BIGIP-21.1.0.2.0.30.22-ENG, 17.5.0 < Hotfix-BIGIP-17.5.1.9.0.160.12-ENG, 17.1.0 < Hotfix-BIGIP-17.1.3.5.0.41.14-ENG · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CISA KEV ↗
  12. Remediation statusRemediation status changed from Patch available to Awaiting fix.
    Before
    Patch available
    After
    Awaiting fix
    CISA KEV ↗
  13. Vendor guidanceAuthoritative vendor guidance changed: removed remediation: cyber.gc.ca/al26-022-vulnerability-impacting-f5-big-ip-access-policy-manager-apm-cve-2026-94127.
    Before
    remediation: cyber.gc.ca/al26-022-vulnerability-impacting-f5-big-ip-access-policy-manager-apm-cve-2026-94127
    After
    no authoritative guidance recorded
    CISA KEV ↗
  14. Affected versionsThe structured affected or fixed version information changed.
    Before
    BIG-IP: 21.1.0 < Hotfix-BIGIP-21.1.0.2.0.30.22-ENG, 17.5.0 < Hotfix-BIGIP-17.5.1.9.0.160.12-ENG, 17.1.0 < Hotfix-BIGIP-17.1.3.5.0.41.14-ENG · Fixed: The Cyber Centre strongly recommends that organizations running affected F5 BIG‑IP APM deployments upgrade to the following vendor-supported fixed hotfix releases: Affected product Affected versions Fixed Versions BIG IP APM Versions 17.1.0 prior to Hotfix-BIGIP-17.1.3.5.0.41.14-ENG Version 17.1.0 Hotfix-BIGIP-17.1.3.5.0.41.14-ENG BIG IP APM Versions 17.5.0 prior to Hotfix-BIGIP-17.5.1.9.0.160.12-ENG Version 17.5.0 Hotfix-BIGIP-17.5.1.9.0.160.12-ENG BIG IP APM Versions 21.1.0 prior to Hotfix-BIGIP-21.1.0.2.0.30.22-ENG Version 21.1.0 Hotfix-BIGIP-21.1.0.2.0.30.22-ENG The Cyber Centre also recommends organizations to: Identify vulnerable BIG IP systems that have both an APM access policy and an OAuth profile configured on a virtual server. Apply the vendor-provided iRule (contact F5 Support to obtain the iRule) Footnote 1 . Review access logs for indicators of compromise (IoC), particularly OAuth authentication failures especially in rapid succession or large volume Footnote 1 . Also review administrative accounts, access policies for any signs of suspicious activity. Upgrade to a vendor-supported fixed software version as soon as possible. Ensure management interfaces are restricted to trusted administrative networks. Follow F5 guidance for vulnerability remediation and validation following patch deployment. Note: Organizations operating Common Criteria Footnote 5 evaluated configurations should review F5's advisory Footnote 1 and apply the recommended updates in accordance with their change management and certification requirements. In addition, the Cyber Centre strongly recommends that organizations review and implement the Cyber Centre’s Top 10 IT Security Actions Footnote 6 with an emphasis on the following topics: Consolidating, monitoring, and defending Internet gateways Patch operating systems and applications Harden operating systems and applications Isolate web-facing applications Should activity matching the content of this alert be discovered, recipients are encouraged to report via My Cyber Portal , or email contact@cyber.gc.ca .
    After
    BIG-IP: 21.1.0 < Hotfix-BIGIP-21.1.0.2.0.30.22-ENG, 17.5.0 < Hotfix-BIGIP-17.5.1.9.0.160.12-ENG, 17.1.0 < Hotfix-BIGIP-17.1.3.5.0.41.14-ENG · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CISA KEV ↗
  15. Remediation statusRemediation status changed from Patch available to Awaiting fix.
    Before
    Patch available
    After
    Awaiting fix
    CISA KEV ↗
  16. Affected versionsThe structured affected or fixed version information changed.
    Before
    BIG-IP: 21.1.0 < Hotfix-BIGIP-21.1.0.2.0.30.22-ENG, 17.5.0 < Hotfix-BIGIP-17.5.1.9.0.160.12-ENG, 17.1.0 < Hotfix-BIGIP-17.1.3.5.0.41.14-ENG · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    BIG-IP: 21.1.0 < Hotfix-BIGIP-21.1.0.2.0.30.22-ENG, 17.5.0 < Hotfix-BIGIP-17.5.1.9.0.160.12-ENG, 17.1.0 < Hotfix-BIGIP-17.1.3.5.0.41.14-ENG · Fixed: The Cyber Centre strongly recommends that organizations running affected F5 BIG‑IP APM deployments upgrade to the following vendor-supported fixed hotfix releases: Affected product Affected versions Fixed Versions BIG IP APM Versions 17.1.0 prior to Hotfix-BIGIP-17.1.3.5.0.41.14-ENG Version 17.1.0 Hotfix-BIGIP-17.1.3.5.0.41.14-ENG BIG IP APM Versions 17.5.0 prior to Hotfix-BIGIP-17.5.1.9.0.160.12-ENG Version 17.5.0 Hotfix-BIGIP-17.5.1.9.0.160.12-ENG BIG IP APM Versions 21.1.0 prior to Hotfix-BIGIP-21.1.0.2.0.30.22-ENG Version 21.1.0 Hotfix-BIGIP-21.1.0.2.0.30.22-ENG The Cyber Centre also recommends organizations to: Identify vulnerable BIG IP systems that have both an APM access policy and an OAuth profile configured on a virtual server. Apply the vendor-provided iRule (contact F5 Support to obtain the iRule) Footnote 1 . Review access logs for indicators of compromise (IoC), particularly OAuth authentication failures especially in rapid succession or large volume Footnote 1 . Also review administrative accounts, access policies for any signs of suspicious activity. Upgrade to a vendor-supported fixed software version as soon as possible. Ensure management interfaces are restricted to trusted administrative networks. Follow F5 guidance for vulnerability remediation and validation following patch deployment. Note: Organizations operating Common Criteria Footnote 5 evaluated configurations should review F5's advisory Footnote 1 and apply the recommended updates in accordance with their change management and certification requirements. In addition, the Cyber Centre strongly recommends that organizations review and implement the Cyber Centre’s Top 10 IT Security Actions Footnote 6 with an emphasis on the following topics: Consolidating, monitoring, and defending Internet gateways Patch operating systems and applications Harden operating systems and applications Isolate web-facing applications Should activity matching the content of this alert be discovered, recipients are encouraged to report via My Cyber Portal , or email contact@cyber.gc.ca .
    Canadian Centre for Cyber Security ↗
  17. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    Canadian Centre for Cyber Security ↗
  18. CISA KEV stateCISA KEV now confirms exploitation in the wild.
    Before
    not listed in CISA KEV
    After
    listed in CISA KEV since 2026-09-22
    CISA KEV ↗
  19. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2026-84427↗Canadian Centre for Cyber Security remediation guidance↗CISA KEV record↗CVE authority or vendor reference · F5 K000162605↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-94127 · cve.blacktree.nl