# CVE-2026-15783: Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed reading private repository metadata via delegated bypass rule suites

> CVE-2026-15783: Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed reading private repository metadata via delegated bypass rule suites. CVSS 5.3 (CVSS 4.0).

Canonical: https://rewindex.com/cve/CVE-2026-15783
Last updated: 2026-10-24T20:10:00Z

- Published: 2026-07-17 15:20 UTC · Updated: 2026-10-24 20:10 UTC · Assigner: GitHub\_P
- CVSS: 5.3 (CVSS 4.0) · Severity: Medium
- EPSS: 0.45%, 39th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-862

## Description

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.

## Affected vendors and products

- GitHub: Enterprise Server

## Tracked companies

- [GitHub](https://rewindex.com/company/github.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-15783)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-15783)
- [https://docs.github.com/en/enterprise-server@3.17/admin/release-notes\#3.17.18](https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.18)
- [https://docs.github.com/en/enterprise-server@3.18/admin/release-notes\#3.18.12](https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.12)
- [https://docs.github.com/en/enterprise-server@3.19/admin/release-notes\#3.19.9](https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.9)
- [https://docs.github.com/en/enterprise-server@3.20/admin/release-notes\#3.20.5](https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.5)
- [https://docs.github.com/en/enterprise-server@3.21/admin/release-notes\#3.21.3](https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.3)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-15783 · Markdown: https://rewindex.com/cve/CVE-2026-15783.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-15783 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:15:49.197Z