CVE-2026-15343

Path traversal vulnerability in GitHub Enterprise Server allowed writing files to arbitrary repository paths, including GitHub Actions workflow files, via unchecked Dependabot dependency-file paths

HIGH
8.6
CVSS Score
Published: July 17, 2026 at 03:18 PM UTC
Updated: October 24, 2026 at 08:10 PM UTC
1 product affected across 1 vendorGitHub Enterprise Server

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Severity
HIGH8.6
Exploit prediction
EPSS 0.8%
SSVC
No known exploit

Description

A path traversal vulnerability was identified in GitHub Enterprise Server that allowed an attacker who had code execution inside the Dependabot updater container to write files to arbitrary repository paths, including GitHub Actions workflow files under .github/workflows/ as the path validation did not check the effective path which the attacker could control through the dependency file's directory and symlink target. If the repository used a pull_request_target workflow or had auto-merge enabled, an injected workflow could execute with access to the repository's GitHub Actions secrets. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.21.3, 3.20.5, 3.19.9, 3.18.12, 3.17.18.

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 automatableTotal impact

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

CVSS

8.6HIGHGitHub_P
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-22

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