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Full vulnerability report · 2026
CVE-2026-107406High confidence

Memory overflow vulnerability leading to Remote Code Execution or Denial of Service

NetScaler · ADC

9.5CriticalCVSS 4.0
Recommended action
Within 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityCriticalOperational priority:Critical, 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 0.47% 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 NetScaler ADC 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-2026-95315

No EUVD known-exploited evidence

Memory overflow vulnerability leading to Remote Code Execution or Denial of Service Vulnerability in NetScaler ADC. NetScaler ADC or NetScaler Gateway must be configured as a SAML SP or SAML IdP, subject to the following version-specific requirements:   * For the following versions: Applicable only when configured as a SAML IdP: * NetScaler ADC and NetScaler Gateway between 14.1-73.37 and 14.1-73.41, inclusive * NetScaler ADC 14.1-FIPS between 14.1-73.37 FIPS and 14.1-73.41 FIPS, inclusive * NetScaler ADC and NetScaler Gateway between 13.1-64.23 and 13.1-64.28, inclusive * NetScaler ADC 13.1-FIPS between 13.1-NDcPP 13.1-37.279 and 13.1- 37.282, inclusive   For the following versions: Applicable only when configured as a SAML SP or SAML IdP: * NetScaler ADC and NetScaler Gateway before 14.1-73.37  * NetScaler ADC 14.1-FIPS before 14.1-73.37 FIPS  * NetScaler ADC and NetScaler Gateway before 13.1-64.23 * NetScaler ADC 13.1-FIPS before13.1-NDcPP 13.1-37.279

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
9.5 · CVSS 4.0
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
01

What, why and how

Memory overflow vulnerability leading to Remote Code Execution or Denial of Service Vulnerability in NetScaler ADC. NetScaler ADC or NetScaler Gateway must be configured as a SAML SP or SAML IdP, subject to the following version-specific requirements:   * For the following versions: Applicable only when configured as a SAML IdP: * NetScaler ADC and NetScaler Gateway between 14.1-73.37 and 14.1-73.41, inclusive * NetScaler ADC 14.1-FIPS between 14.1-73.37 FIPS and 14.1-73.41 FIPS, inclusive * NetScaler ADC and NetScaler Gateway between 13.1-64.23 and 13.1-64.28, inclusive * NetScaler ADC 13.1-FIPS between 13.1-NDcPP 13.1-37.279 and 13.1- 37.282, inclusive   For the following versions: Applicable only when configured as a SAML SP or SAML IdP: * NetScaler ADC and NetScaler Gateway before 14.1-73.37  * NetScaler ADC 14.1-FIPS before 14.1-73.37 FIPS  * NetScaler ADC and NetScaler Gateway before 13.1-64.23 * NetScaler ADC 13.1-FIPS before13.1-NDcPP 13.1-37.279

What

Memory overflow vulnerability leading to Remote Code Execution or Denial of Service Vulnerability in NetScaler ADC. NetScaler ADC or NetScaler Gateway must be configured as a SAML SP or SAML IdP, subject to the following version-specific requirements:   * For the following versions: Applicable only when configured as a SAML IdP: * NetScaler ADC and NetScaler Gateway between 14.1-73.37 and 14.1-73.41, inclusive * NetScaler ADC 14.1-FIPS between 14.1-73.37 FIPS and 14.1-73.41 FIPS, inclusive * NetScaler ADC and NetScaler Gateway between 13.1-64.23 and 13.1-64.28, inclusive * NetScaler ADC 13.1-FIPS between 13.1-NDcPP 13.1-37.279 and 13.1- 37.282, inclusive   For the following versions: Applicable only when configured as a SAML SP or SAML IdP: * NetScaler ADC and NetScaler Gateway before 14.1-73.37  * NetScaler ADC 14.1-FIPS before 14.1-73.37 FIPS  * NetScaler ADC and NetScaler Gateway before 13.1-64.23 * NetScaler ADC 13.1-FIPS before13.1-NDcPP 13.1-37.279

Why

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

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

Memory overflow vulnerability leading to Remote Code Execution or Denial of Service Vulnerability in NetScaler ADC. NetScaler ADC or NetScaler Gateway must be configured as a SAML SP or SAML IdP, subject to the following version-specific requirements:   * For the following versions: Applicable only when configured as a SAML IdP: * NetScaler ADC and NetScaler Gateway between 14.1-73.37 and 14.1-73.41, inclusive * NetScaler ADC 14.1-FIPS between 14.1-73.37 FIPS and 14.1-73.41 FIPS, inclusive * NetScaler ADC and NetScaler Gateway between 13.1-64.23 and 13.1-64.28, inclusive * NetScaler ADC 13.1-FIPS between 13.1-NDcPP 13.1-37.279 and 13.1- 37.282, inclusive   For the following versions: Applicable only when configured as a SAML SP or SAML IdP: * NetScaler ADC and NetScaler Gateway before 14.1-73.37  * NetScaler ADC 14.1-FIPS before 14.1-73.37 FIPS  * NetScaler ADC and NetScaler Gateway before 13.1-64.23 * NetScaler ADC 13.1-FIPS before13.1-NDcPP 13.1-37.279

Why

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

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.
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 → Improper Restriction of Operations within the Bounds of a Memory Buffer → execute code or commands in the affected security context
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-119 ↗

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer. The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

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:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:L

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.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.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.SCHighSubsequent-system confidentiality: A successful attack can cause a major loss.SIHighSubsequent-system integrity: A successful attack can cause a major loss.SALowSubsequent-system availability: A successful attack can cause a limited loss.
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 executionDenial of serviceCWE-119
A

Official authority intelligence

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

ENISA EUVD · EUVD-2026-95315Official EUVD mapping

Memory overflow vulnerability leading to Remote Code Execution or Denial of Service Vulnerability in NetScaler ADC. NetScaler ADC or NetScaler Gateway must be configured as a SAML SP or SAML IdP, subject to the following version-specific requirements:   * For the following versions: Applicable only when configured as a SAML IdP: * NetScaler ADC and NetScaler Gateway between 14.1-73.37 and 14.1-73.41, inclusive * NetScaler ADC 14.1-FIPS between 14.1-73.37 FIPS and 14.1-73.41 FIPS, inclusive * NetScaler ADC and NetScaler Gateway between 13.1-64.23 and 13.1-64.28, inclusive * NetScaler ADC 13.1-FIPS between 13.1-NDcPP 13.1-37.279 and 13.1- 37.282, inclusive   For the following versions: Applicable only when configured as a SAML SP or SAML IdP: * NetScaler ADC and NetScaler Gateway before 14.1-73.37  * NetScaler ADC 14.1-FIPS before 14.1-73.37 FIPS  * NetScaler ADC and NetScaler Gateway before 13.1-64.23 * NetScaler ADC 13.1-FIPS before13.1-NDcPP 13.1-37.279

Official EUVD record ↗
BSI · German · WID-SEC-2026-3847Citrix NetScaler ADC und Gateway: Schwachstelle ermöglicht Codeausführung und DoS

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Citrix Systems NetScaler ausnutzen, um beliebigen Programmcode auszuführen und um einen Denial of Service Angriff durchzuführen.

Official advisory ↗
Canadian Centre for Cyber Security · English · AV26-1023Citrix security advisory (AV26-1023)

The Cyber Centre encourages users and administrators to review the provided web links and apply any necessary updates as they become available.

Official advisory ↗
Canadian Centre for Cyber Security · English · AL26-024AL26-024 - Critical vulnerabilities affecting Citrix NetScaler ADC and NetScaler Gateway – CVE-2026-88771 and CVE-2026-88772 – Update 2

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 ↗
Cyber Security Agency of Singapore · English · CSA-SB-20261021Security Bulletin 21 Oct 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 21 Oct 2026, published on 21 October 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20261014Security Bulletin 14 Oct 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 14 Oct 2026, published on 14 October 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
INCIBE-CERT · Spanish · desbordamiento-de-memoria-en-netscaler-adc-y-netscaler-gateway-de-citrixDesbordamiento de memoria en NetScaler ADC y NetScaler Gateway de Citrix

Michael Tucker, Chew Keong Tan y Alex Bernier, del equipo JPMorgan Chase XOR Team, y Maxim Suhanov han informado sobre una vulnerabilidad de severidad crítica que, en caso de ser explotada, podría permitir a un atacante remoto no autenticado ejecutar código arbitrario o provocar una denegación de servicio (DoS).

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1285Avis du CERT-FR

Une vulnérabilité a été découverte dans Citrix NetScaler ADC et Gateway. Elle permet à un attaquant de provoquer une exécution de code arbitraire à distance et un déni de service à distance.

Official advisory ↗
CSIRT Italia · Italian · rilevata-vulnerabilita-in-prodotti-citrix-netscalerRilevata vulnerabilità in prodotti Citrix NetScaler

Citrix ha rilasciato aggiornamenti di sicurezza per risolvere una vulnerabilità con gravità "critica" presente nei prodotti NetScaler ADC e Gateway. Tale vulnerabilità, sfruttabile solo quando le funzionalità SAML sono abilitate sui prodotti target, potrebbe consentire ad un utente malintenzionato remoto di eseguire codice arbitrario o di compromettere la disponibilità del servizio sui sistemi interessati.

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6985Citrix 제품 보안 업데이트 권고

NetScaler ADC, NetScaler Gateway에서 발생하는 Improper Restriction of Operations within the Bounds of a Memory Buffer 취약점(CVE-2026-107406) [1][2]

Official advisory ↗
NCSC-NL · Dutch · NCSC-2026-0410Kwetsbaarheid verholpen in Citrix NetScaler ADC en Gateway

A memory overflow vulnerability in specific versions of NetScaler ADC and Gateway configured as SAML SP or IdP can result in remote code execution or denial of service.

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
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
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 8 Oct 2026 · Last source change 10 Oct 2026, 03:55 UTC · CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer

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 2026-10-09
European sourceENISA EUVD · EUVD-2026-95315
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD awaiting enrichment

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. Remediation statusRemediation status changed from Awaiting fix to Mitigation available.
    Before
    Awaiting fix
    After
    Mitigation available
    Canadian Centre for Cyber Security ↗
  3. ENISA EUVD mappingEUVD-2026-95315 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-95315"}
    ENISA EUVD ↗
  4. Vendor guidanceAuthoritative vendor guidance changed: removed patch: community.citrix.com/protecting-customers-immediate-guidance-for-cve-2026-107406-in-netscaler-adc-and-netscaler-gateway-r1631; removed remediation: community.citrix.com/protecting-customers-immediate-guidance-for-cve-2026-107406-in-netscaler-adc-and-netscaler-gateway-r1631.
    Before
    patch: community.citrix.com/protecting-customers-immediate-guidance-for-cve-2026-107406-in-netscaler-adc-and-netscaler-gateway-r1631 · remediation: community.citrix.com/protecting-customers-immediate-guidance-for-cve-2026-107406-in-netscaler-adc-and-netscaler-gateway-r1631
    After
    no authoritative guidance recorded
    CNA ↗
  5. Affected versionsThe structured affected or fixed version information changed.
    Before
    ADC: < 14.1-73.46, < 13.1-64.29, < 14.1-73.46 FIPS, < 13.1.37.283 FIPS; Gateway: < 14.1-73.46, < 13.1-64.29 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    ADC: < 14.1-73.46, < 13.1-64.29, < 14.1-73.46 FIPS, < 13.1.37.283 FIPS; Gateway: < 14.1-73.46, < 13.1-64.29 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
  6. Remediation statusRemediation status changed from Patch available to Awaiting fix.
    Before
    Patch available
    After
    Awaiting fix
    CNA ↗
  7. Vendor guidanceAuthoritative vendor guidance changed: added patch: community.citrix.com/protecting-customers-immediate-guidance-for-cve-2026-107406-in-netscaler-adc-and-netscaler-gateway-r1631; added remediation: community.citrix.com/protecting-customers-immediate-guidance-for-cve-2026-107406-in-netscaler-adc-and-netscaler-gateway-r1631.
    Before
    no authoritative guidance recorded
    After
    patch: community.citrix.com/protecting-customers-immediate-guidance-for-cve-2026-107406-in-netscaler-adc-and-netscaler-gateway-r1631 · remediation: community.citrix.com/protecting-customers-immediate-guidance-for-cve-2026-107406-in-netscaler-adc-and-netscaler-gateway-r1631
    community.citrix.com ↗
  8. Affected versionsThe structured affected or fixed version information changed.
    Before
    ADC: < 14.1-73.46, < 13.1-64.29, < 14.1-73.46 FIPS, < 13.1.37.283 FIPS; Gateway: < 14.1-73.46, < 13.1-64.29 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    ADC: < 14.1-73.46, < 13.1-64.29, < 14.1-73.46 FIPS, < 13.1.37.283 FIPS; Gateway: < 14.1-73.46, < 13.1-64.29 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    CNA ↗
  9. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    community.citrix.com ↗
  10. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Remediation guidance recorded
ENISA EUVD · EUVD-2026-95315↗Canadian Centre for Cyber Security remediation guidance↗CVE authority or vendor reference↗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-2026-107406 · cve.blacktree.nl