Auth bypass in Github Enterprise Server

CVE-2025-8447

An improper access control vulnerability was identified in GitHub Enterprise Server that allowed users with access to any repository to retrieve limited code content from another repository by creating a diff between the repositories. To exploit this vulnerability, an attacker needed to know the name of a private repository along with its branches, tags, or commit SHAs that they could use to trigger compare/diff functionality and retrieve limited code without proper authorization. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.18, and was fixed in versions 3.14.17, 3.15.12, 3.16.8 and 3.17.5. This vulnerability was reported via the GitHub Bug Bounty program.

Vulnerability class: IDOR (Insecure Direct Object Reference)

EPSS: 0.003 (22.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-8447?
CVE-2025-8447 is a low-severity vulnerability in Github Enterprise Server, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 3.1/10. Published 2025-08-26.
How severe is CVE-2025-8447?
Low severity. CVSS v3 base score is 3.1 out of 10.
Is CVE-2025-8447 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.