CVE-2026-5512: GitHub Enterprise Server · Insertion of sensitive information into sent data
Affects GitHub Enterprise ServerSource CVE Database V5
Not known to be exploited · CVSS 5.3 Medium · fixed in 3.20.1 : update GitHub Enterprise Server when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.20.1
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:L/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 21 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| GitHubEnterprise Server | Affected
| Fixed in– |
AI-suggested
This vulnerability has been fixed in GitHub Enterprise Server versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, and 3.14.26. Users should upgrade to one of these fixed versions or later to remediate the issue. Since this is an on-premises product, administrators must apply the appropriate update. No other mitigation or workaround is indicated in the available data.
Description
CVE-2026-5512 is an improper authorization vulnerability in GitHub Enterprise Server prior to version 3.21. It allows an authenticated attacker to discover the names of private repositories by their numeric IDs due to insufficient authorization checks in the mobile upload policy API endpoint. Validation error messages exposed full repository names even when the caller lacked access. This issue was fixed in versions 3.20.1 and later. The vulnerability has a medium severity rating with a CVSS score of 5.3 and was reported through the GitHub Bug Bounty program.
References
- docs.github.com/en/enterprise-server@3.14/admin/release-notes (opens in a new tab)
- docs.github.com/en/enterprise-server@3.15/admin/release-notes (opens in a new tab)
- docs.github.com/en/enterprise-server@3.16/admin/release-notes (opens in a new tab)
- docs.github.com/en/enterprise-server@3.17/admin/release-notes (opens in a new tab)
- docs.github.com/en/enterprise-server@3.18/admin/release-notes (opens in a new tab)
- docs.github.com/en/enterprise-server@3.19/admin/release-notes (opens in a new tab)
- docs.github.com/en/enterprise-server@3.20/admin/release-notes (opens in a new tab)