CVE-2026-15783

Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed reading private repository metadata via delegated bypass rule suites

MEDIUM
5.3
CVSS Score
Published: July 17, 2026 at 03:20 PM UTC
Updated: October 24, 2026 at 08:10 PM UTC
1 product affected across 1 vendorGitHub Enterprise Server

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

3.17.0 ≤ v ≤ 3.17.173.18.0 ≤ v ≤ 3.18.113.19.0 ≤ v ≤ 3.19.83.20.0 ≤ v ≤ 3.20.43.21.0 ≤ v ≤ 3.21.23.17.03.18.03.19.03.20.03.21.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMGitHub_P
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-862

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