CVE-2026-15783 json
Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed reading private repository metadata via delegated bypass rule suites
published 2026-07-17 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-45191
- cvss
- 5.3
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 39%
- public exploits
- 0
- none known
Summary
A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user with write access to any repository to read metadata from private repositories they did not have access to, including private repository owners and names, branch names, commit SHAs, commit messages, and the pushing actor. The delegated bypass endpoint resolved a rule suite directly from an attacker-supplied, encoded identifier without verifying that the requesting user could read the rule suite's repository, and because these identifiers are sequential an attacker could enumerate them across the instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.18, 3.18.12, 3.19.9, 3.20.5, and 3.21.3. This vulnerability was reported via the GitHub Bug Bounty program.
Patch / fix
- GitHub Enterprise Server 3.17.18, 3.18.12, 3.19.9, 3.20.5, 3.21.3
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N |
| CNA | 4.0 | 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/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 |
Affected products
- GitHub Enterprise Server
Classification
- Weakness
-
- CWE-862 Missing Authorization
References
-
docs.github.com
/en/enterprise-server@3.17/admin/release-notes#3.17.18
release-notes
-
docs.github.com
/en/enterprise-server@3.18/admin/release-notes#3.18.12
release-notes
-
docs.github.com
/en/enterprise-server@3.19/admin/release-notes#3.19.9
release-notes
-
docs.github.com
/en/enterprise-server@3.20/admin/release-notes#3.20.5
release-notes
-
docs.github.com
/en/enterprise-server@3.21/admin/release-notes#3.21.3
release-notes
Sources
- CVE List CVE-2026-15783
- NVD CVE-2026-15783
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CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.