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TI-2026-12126 Aliases CVE-2026-14340GHSA-86rx-87q3-fqhc

Incorrect authorization in GitHub Enterprise Server

Priority LOW 24CWE-863Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · Low · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-863.

Summary

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed a user-to-server token scoped to a GitHub App installation to perform certain write operations on public repositories outside the token's intended scope. This was possible because the authorization check only verified that the installation had read permissions on the target repository rather than verifying that the token's installation was explicitly granted access to that repository. An attacker who obtained a victim's user-to-server token could create issues, issue comments, commit comments, and private vulnerability reports on any public repository, appearing as the victim user with no indication of the app involvement. This vulnerability was fixed by adding a repository scope check for user-to-server tokens issued by global apps. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.21.2, 3.20.4, 3.19.8, 3.18.11, 3.17.17, 3.16.20. This vulnerability was reported via the GitHub Bug Bounty program.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00427 37th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
GitHubEnterprise Server3.16.0 – 3.16.19; 3.17.0 – 3.17.16; 3.18.0 – 3.18.10; 3.19.0 – 3.19.7; 3.20.0 – 3.20.3; 3.21.0 – 3.21.1—No fix listedCNA
  • Enterprise Server VendorGitHub Affected 3.16.0 – 3.16.19; 3.17.0 – 3.17.16; 3.18.0 – 3.18.10; 3.19.0 – 3.19.7; 3.20.0 – 3.20.3; 3.21.0 – 3.21.1 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*before 3.16.20; 3.17.0 to before 3.17.17; 3.18.0 to before 3.18.11; 3.19.0 to before 3.19.8; 3.20.0 to before 3.20.4; 3.21.0 to before 3.21.2VulnerableGitHub
  • cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:* Versions before 3.16.20; 3.17.0 to before 3.17.17; 3.18.0 to before 3.18.11; 3.19.0 to before 3.19.8; 3.20.0 to before 3.20.4; 3.21.0 to before 3.21.2 Vulnerable ·GitHub

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-14340
  2. 2026-10-03 Alias added: GHSA-86rx-87q3-fqhc

References

Other 6

  • TI-2024-04632 An authentication bypass vulnerability was present in the GitHub Enterprise Server (GHES)… CVSS 4.0CRITICAL 10.0
  • TI-2024-00181 Unsafe Reflection in Github Enterprise Server leading to Command Injection CVSS 3.1CRITICAL 9.8
  • TI-2024-00466 Privilege Escalation by Code Injection in the Management Console in GitHub Enterprise Server CVSS 3.1HIGH 8.8
  • TI-2026-03340 Remote code execution via git push option injection in GitHub Enterprise Server CVSS 4.0HIGH 8.7
  • TI-2024-08804 Improper signature verification in GitHub Enterprise Server CVSS 4.0CRITICAL 9.5
  • TI-2026-08177 Server-side request forgery in GitHub Enterprise Server CVSS 4.0CRITICAL 9.2
See all 125 →

Sources

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