CVE-2026-3307

Description

An authorization bypass vulnerability was identified in GitHub Enterprise Server that allowed an attacker with admin access on one repository to modify the secret scanning push protection delegated bypass reviewer list on another repository by manipulating the owner_id parameter in the request body. Authorization was verified against the repository in the URL, but the action was applied to a different repository specified in the request body. The impact is limited to assigning existing trusted users as bypass reviewers; it does not allow adding arbitrary external users. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.14.25, 3.15.20, 3.16.16, 3.17.13, 3.18.7, 3.19.4 and 3.20.1. This vulnerability was reported via the GitHub Bug Bounty program.

CVSS v3.1 Score

2.7

LOW

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

EPSS — Exploit Prediction

0.0004

Probability of exploitation

0.13%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-639 CWE-639

Affected Products

Vendor	Product	Versions
github	enterprise_server	< 3.14.26
github	enterprise_server	3.15.0 — 3.15.21
github	enterprise_server	3.16.0 — 3.16.17
github	enterprise_server	3.17.0 — 3.17.14
github	enterprise_server	3.18.0 — 3.18.8
github	enterprise_server	3.19.0 — 3.19.5
github	enterprise_server	All

References

Advisories & Patches

https://docs.github.com/en/[email protected]/admin/release-notes#3.14.25 https://docs.github.com/en/[email protected]/admin/release-notes#3.15.20 https://docs.github.com/en/[email protected]/admin/release-notes#3.16.16 https://docs.github.com/en/[email protected]/admin/release-notes#3.17.13 https://docs.github.com/en/[email protected]/admin/release-notes#3.18.7 https://docs.github.com/en/[email protected]/admin/release-notes#3.19.4 https://docs.github.com/en/[email protected]/admin/release-notes#3.20.1

Frequently Asked Questions

What is CVE-2026-3307? +

An authorization bypass vulnerability was identified in GitHub Enterprise Server that allowed an attacker with admin access on one repository to modify the secret scanning push protection delegated bypass reviewer list on another repository by manipulating the owner_id parameter in the request body. Authorization was verified against the repository in the URL, but the action was applied to a different repository specified in the request body. The impact is limited to assigning existing trusted users as bypass reviewers; it does not allow adding arbitrary external users. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.14.25, 3.15.20, 3.16.16, 3.17.13, 3.18.7, 3.19.4 and 3.20.1. This vulnerability was reported via the GitHub Bug Bounty program. It has a CVSS v3.1 base score of 2.7 (LOW).

How severe is CVE-2026-3307? +

CVE-2026-3307 has a CVSS v3.1 score of 2.7 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0004, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-3307? +

CVE-2026-3307 affects products from github, specifically: enterprise_server. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-3307? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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