CVE-2026-5845
published 2026-04-21CVE-2026-5845: An improper authorization vulnerability in scoped user-to-server (ghu_) token authorization in GitHub Enterprise Server allows an authenticated attacker to…
PriorityP262critical9.6CVSS 3.1
AVNACLPRLUINSCCHIHAN
EPSS
0.23%
13.8th percentile
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.
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| github | enterprise_server | < 3.14.26 | 3.14.26 |
| github | enterprise_server | — | — |
| github | enterprise_server | 3.14.0 – 3.14.25 | — |
| github | enterprise_server | >= 3.15.0 < 3.15.21 | 3.15.21 |
| github | enterprise_server | 3.15.0 – 3.15.20 | — |
| github | enterprise_server | >= 3.16.0 < 3.16.17 | 3.16.17 |
| github | enterprise_server | 3.16.0 – 3.16.16 | — |
| github | enterprise_server | >= 3.17.0 < 3.17.14 | 3.17.14 |
| github | enterprise_server | 3.17.0 – 3.17.13 | — |
| github | enterprise_server | >= 3.18.0 < 3.18.8 | 3.18.8 |
| github | enterprise_server | 3.18.0 – 3.18.7 | — |
| github | enterprise_server | >= 3.19.0 < 3.19.5 | 3.19.5 |
| github | enterprise_server | 3.19.0 – 3.19.4 | — |
| github | enterprise_server | >= 3.20.0 < 3.20.1 | 3.20.1 |
CVSS provenance
nvdv3.19.6CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
nvdv4.07.2HIGHCVSS: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
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https://docs.github.com/en/[email protected]/admin/release-notes#3.14.26https://docs.github.com/en/[email protected]/admin/release-notes#3.15.21https://docs.github.com/en/[email protected]/admin/release-notes#3.16.17https://docs.github.com/en/[email protected]/admin/release-notes#3.17.14https://docs.github.com/en/[email protected]/admin/release-notes#3.18.8https://docs.github.com/en/[email protected]/admin/release-notes#3.19.5https://docs.github.com/en/[email protected]/admin/release-notes#3.20.1
2026-04-21
Published