CVE-2026-5845
Improper authorization fallback allows scoped user-to-server token installation escape in GitHub Enterprise Server
- Published
- Updated
- Reserved
- Assigned by
- GitHub_P
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_PCNA (assigner) | 4.0 | High7.2 | 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 |
| NVDNVD · Analyzed | 4.0 | High7.2 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.29% · top 78% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.2.
Weakness
Affected products
- affected 3.20.0 – < 3.20.1
- affected 3.19.0 – ≤ 3.19.4
- affected 3.18.0 – ≤ 3.18.7
- affected 3.17.0 – ≤ 3.17.13
- affected 3.16.0 – ≤ 3.16.16
- affected 3.15.0 – ≤ 3.15.20
- affected 3.14.0 – ≤ 3.14.25
References (7)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.1 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.5 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.8 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.14 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.16.17 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.15.21 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.14.26 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-5845)Record last updated .