Cyber Resilience

CVE-2026-4524

Auth Bypass in Gitlab 18.9.1 – 18.9.7

Auth Bypass
Published
14 May 2026
Modified
17 June 2026
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0029 21th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-4524 is a medium-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Gitlab Gitlab. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability Data

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.9.1 before 18.9.7, 18.10 before 18.10.6, and 18.11 before 18.11.3 that could have allowed an authenticated user to access confidential issue content in public projects without proper authorization…

more

due to improper authorization checks.

CWE(s)
CWE-288

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
Why these techniques?

Authz bypass in public-facing GitLab enables direct exploitation (T1190) and unauthorized data access equivalent to privilege escalation (T1068).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-1747Same product: Gitlab Gitlab
CVE-2026-2745Same product: Gitlab Gitlab
CVE-2025-0549Same product: Gitlab Gitlab
CVE-2026-3607Same product: Gitlab Gitlab
CVE-2025-9825Same product: Gitlab Gitlab
CVE-2025-11984Same product: Gitlab Gitlab
CVE-2026-0602Same product: Gitlab Gitlab
CVE-2024-1525Same product: Gitlab Gitlab
CVE-2026-5173Same product: Gitlab Gitlab
CVE-2026-1752Same product: Gitlab Gitlab

Affected Assets

gitlab
gitlab
18.9.1 — 18.9.7 · 18.9.1 — 18.9.7 · 18.10.0 — 18.10.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-6 Least Privilege
  • AC-4 Information Flow Enforcement
Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 7 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.3
  • V6.6.1
  • V12.1.3

Mitigating Controls (NIST 800-53 r5) AI

AC-3 Access Enforcement good match
prevent

Directly enforces authorization decisions on confidential issue objects so an authenticated user cannot bypass checks to read restricted content.

AC-6 Least Privilege partial match
prevent

Limits the privileges granted to ordinary authenticated users, reducing the impact surface if an authorization check for confidential issues is missing.

AC-4 Information Flow Enforcement partial match
prevent

Enforces information-flow rules that would block unauthorized disclosure of confidential issue data between users and projects.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 full match
prevents

Requiring authentication on every channel and path directly eliminates alternate-path bypasses.

PR.AA-05 mostly match
prevents

Enforcing authorizations and least privilege across all access vectors prevents unauthenticated alternate paths.

PR.IR-01 mostly match
prevents

Protecting networks and environments from unauthorized logical access blocks bypass via undocumented channels.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
detects

Security testing can detect alternate-path bypasses but does not prevent them in production.

A.8.5 Secure authentication mostly match
degrades

Secure authentication control directly mitigates bypass by requiring strong, consistent authentication on all paths.

A.5.15 Access control partial match
prevents

Access control policy directly addresses alternate authentication paths by requiring all channels to enforce authentication.

A.5.17 Authentication information partial match
degrades

Authentication information management ensures credentials and mechanisms are consistently applied across all access paths.

A.5.18 Access rights partial match
prevents

Access rights provisioning and review prevent bypass via unmonitored or alternate channels.

A.8.2 Privileged access rights partial match
prevents

Privileged access rights control reduces risk of bypass through elevated or alternate paths.

References