Vulnerability Report

CVE-2026-5845

Title: Improper authorization for scoped user-to-server tokens

Auth Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2026-5845.

CWE Category CWE-639
Published Date Apr 21, 2026
Modified Date Apr 29, 2026
Exploit Status Not Found
Score 7.2 CVSS v4.0
Exploit Probability (EPSS)
0.03%

Vulnerability Summary

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 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.

Impacted Vendors

B
blackberry 1
G
github 1

Reference Links

https://docs.github.com/en/[email protected]/admin/release-notes#3.14.26 https://docs.github.com/en/[email protected]/admin/release-notes#3.15.21 https://docs.github.com/en/[email protected]/admin/release-notes#3.16.17 https://docs.github.com/en/[email protected]/admin/release-notes#3.17.14 https://docs.github.com/en/[email protected]/admin/release-notes#3.18.8 https://docs.github.com/en/[email protected]/admin/release-notes#3.19.5 https://docs.github.com/en/[email protected]/admin/release-notes#3.20.1
CVSS v4.0
Source Entity [email protected]
Severity HIGH
7.2
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
N/A
RAW VECTOR 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
CVSS v3.1
Source Entity [email protected]
Severity CRITICAL
9.6
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
CHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-5845 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector LOCAL
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String 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

Affected Stack

No specific products linked.