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Full vulnerability report · 2026
CVE-2026-34019High confidence

BIG-IP BFD vulnerability

F5 · BIG-IP

Official source article: F5 K000150508 ↗. Check the applicable product and release in the original source.

6.3MediumCVSS 4.0
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.40% 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.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs F5 BIG-IP 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: As exposure requiresRemediation target: Within 365 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-2026-29963

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

When Bidirectional Forwarding Detection (BFD) is configured in Static and Dynamic routing protocols, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to stop processing BFD packets and cause the configured routing protocol to fail over.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

What

When Bidirectional Forwarding Detection (BFD) is configured in Static and Dynamic routing protocols, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to stop processing BFD packets and cause the configured routing protocol to fail over.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Why

The product's resource pool is not large enough to handle peak demand, which allows an attacker to prevent others from accessing the resource by using a (relatively) large number of requests for resources.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

When Bidirectional Forwarding Detection (BFD) is configured in Static and Dynamic routing protocols, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to stop processing BFD packets and cause the configured routing protocol to fail over.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Why

The product's resource pool is not large enough to handle peak demand, which allows an attacker to prevent others from accessing the resource by using a (relatively) large number of requests for resources.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

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.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

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 → Insufficient Resource Pool → cause the confidentiality, integrity or availability impact described by the vendor
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-410 ↗

CWE-410: Insufficient Resource Pool. The product's resource pool is not large enough to handle peak demand, which allows an attacker to prevent others from accessing the resource by using a (relatively) large number of requests for resources.

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:P/PR:N/UI:N/VC:N/VI:N/VA:L/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.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VALowVulnerable-system availability: A successful attack can cause a limited 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
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-410
A

Official authority intelligence

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

Cyber Security Agency of Singapore · English · CSA-SB-20260520Security Bulletin 20 May 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 20 May 2026, published on 20 May 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0591Multiples vulnérabilités dans les produits F5

e service à distance. Solutions Se référer au bulletin de sécurité de l'éditeur pour l'obtention des correctifs (cf. section Documentation). Documentation Bulletin de sécurité F5 K000160932 du 13 mai 2026 https://my.f5.com/manage/s/article/K000160932 Référence CVE CVE-2026-20916 https://www.cve.org/CVERecord?id=CVE-2026-20916 Référence CVE CVE-2026-24464 https://www.cve.org/CVERecord?id=CVE-2026-24464 Référence CVE CVE-2026-28758 https://www.cve.org/CVERecord?id=CVE-2026-28758 Référence CVE CVE-2026-32643 https://www.cve.org/CVERecord?id=CVE-2026-32643 Référence CVE CVE-2026-32673 https://www.cve.org/CVERecord?id=CVE-2026-32673 Référence CVE CVE-2026-34019 https://www.cve.org/CVERecord?id=CVE-2026-34019 Référence CVE CVE-2026-34176 https://www.cve.org/CVERecord?id=CVE-2026-34176 Référence CVE CVE-2026-35062 https://www.cve.org/CVERecord?id=CVE-2026-35062 Référence CVE CVE-2026-39455 https://www.cve.org/CVERecord?id=CVE-2026-39455 Référence CVE CVE-2026-39458 https://www.cve.org/CVERecord?id=CVE-2026-39458 Référence CVE CVE-2026-39459 https://www.cve.org/CVERecord?id=CVE-2026-39459 Référence CVE CVE-2026-40060 https://www.cve.org/CVERecord?id=CVE-2026-40060 Référence CVE CVE-2026-40061 https://www.cve.org/CVERecord?id=CVE-2026-40061 Référence CVE CVE-2026-40067 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-021594F5 NetworksのBIG-IP Access Policy Manager (APM)等の複数製品における不十分なリソースプールに関する脆弱性

双方向転送検出(BFD)が静的および動的ルーティングプロトコルに設定されている場合、未公開のトラフィックがトラフィック管理マイクロカーネル(TMM)においてBFDパケットの処理停止を引き起こし、設定されたルーティングプロトコルでフェイルオーバーを発生させる可能性があります。注意:技術サポート終了(EoTS)に達したソフトウェアバージョンは評価対象外としています。

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 < 17.5.1, 17.1.0 < 17.1.3, 16.1.0 < *
Fixed
BIG-IP: 21.0.0 < *
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
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 13 May 2026 · Last source change 13 May 2026, 16:16 UTC · CWE-410 · Insufficient Resource Pool

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 2026-08-14
European sourceENISA EUVD · EUVD-2026-29963
Product sourceCNA
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 ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
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-2026-34019 · cve.blacktree.nl