CVE-2026-5845
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 4.0
- 7.2 HIGHCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.29% probability · 21th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-639
- Affected
- github/enterprise server
- Source
- product-cna@github.com
EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.26Release Notes, Vendor Advisory
- https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.21Release Notes, Vendor Advisory
- https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.17Release Notes, Vendor Advisory
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.14Release Notes, Vendor Advisory
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.8Release Notes, Vendor Advisory
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.5Release Notes, Vendor Advisory
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.1Release Notes, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.