CVE-2026-5845 (GCVE-0-2026-5845)

Vulnerability from cvelistv5 – Published: 2026-04-21 22:42 – Updated: 2026-04-22 18:04
VLAI?
Title
Improper authorization fallback allows scoped user-to-server token installation escape in GitHub Enterprise Server
Summary
An improper authorization vulnerability in scoped user-to-server (ghu_) token authorization in GitHub Enterprise Server allows an authenticated attacker to access private repositories outside the intended installation scope, which can include write operations, via an authorization fallback that treated a revoked/deleted installation as a global installation context, which could be chained with token revocation timing and SSH push attribution to obtain and reuse a victim-scoped token. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, and 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.
Severity ?
7.2 (High)
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N
CWE
  • CWE-639 - Authorization bypass through User-Controlled key
Assigner
References
Impacted products
Vendor Product Version
GitHub Enterprise Server Affected: 3.20.0 , < 3.20.1 (semver)
Affected: 3.19.0 , ≤ 3.19.4 (semver)
Affected: 3.18.0 , ≤ 3.18.7 (semver)
Affected: 3.17.0 , ≤ 3.17.13 (semver)
Affected: 3.16.0 , ≤ 3.16.16 (semver)
Affected: 3.15.0 , ≤ 3.15.20 (semver)
Affected: 3.14.0 , ≤ 3.14.25 (semver)
Create a notification for this product.
Credits
ahacker1
Show details on NVD website
To clipboard 

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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.