Authorization bypass vulnerability in GitHub Enterprise Server allowed reading of private pull request diffs and patches via repository name collision

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-75101
StatePUBLISHED
AssignerGitHub_P
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-22 21:17:31 UTC
Updated2026-10-02 18:46:47 UTC
DescriptionAn authorization bypass vulnerability was identified in GitHub Enterprise Server that allowed any authenticated user of the instance to read the raw diff or patch of pull requests in private repositories without authorization. Access tokens for raw pull request diffs and patches were scoped to the repository name and pull request number rather than to a globally unique repository identifier, so an attacker who created a repository and pull request matching a target's repository name and pull request number could use a token for their own repository to retrieve the private pull request's contents. Exploitation required the attacker to know the target repository's name and a valid pull request number. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.21, 3.18.15, 3.19.12, 3.20.8, and 3.21.6. This vulnerability was reported via the GitHub Bug Bounty program.

Risk And Classification

Primary CVSS: v4.0 6 MEDIUM from [email protected]

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/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: 0.004490000 probability, percentile 0.363840000 (date 2026-09-25)

Problem Types: CWE-639 | CWE-639 CWE-639 Authorization Bypass Through User-Controlled Key

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary6MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS6MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
3.1[email protected]Primary6.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
Low
User Interaction
None
Confidentiality
High
Integrity
None
Availability
None
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/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 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Github Enterprise Server All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA GitHub Enterprise Server affected 3.17.0 3.17.* semver Not specified
CNA GitHub Enterprise Server affected 3.18.0 3.18.* semver Not specified
CNA GitHub Enterprise Server affected 3.19.0 3.19.* semver Not specified
CNA GitHub Enterprise Server affected 3.20.0 3.20.* semver Not specified
CNA GitHub Enterprise Server affected 3.21.0 3.21.* semver Not specified

References

ReferenceSourceLinkTags
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
docs.github.com/en/[email protected]/admin/release-notes [email protected] docs.github.com Release Notes, Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: syvb (en)

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