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
Description
A path traversal vulnerability was identified in GitHub Enterprise Server that allowed an attacker with code execution inside a Dependabot updater container to write files to arbitrary repository paths, including GitHub Actions workflow files under .github/workflows/, because path validation did not check the actual write destination. The initial fix in versions 3.21.3, 3.20.5, 3.19.9, 3.18.12, and 3.17.18 was incomplete because validation checked the supplied symlink target, while the publisher wrote the file using its directory and name. Writing GitHub Actions workflow files required the Dependabot installation to have workflows: write permission. Depending on repository permissions and workflow configuration, including a relevant pull_request_target workflow or auto-merge, an injected workflow could execute with access to GitHub Actions secrets. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.23 and was fully fixed in versions 3.22.3, 3.21.8, 3.20.10, and 3.19.14. This vulnerability was reported via the GitHub Bug Bounty program.
INFO
Published Date :
July 17, 2026, 4:17 p.m.
Last Modified :
Nov. 3, 2026, 11:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | HIGH | 82327ea3-741d-41e4-88f8-2cf9e791e760 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update GitHub Enterprise Server to version 3.21.3 or later.
- Apply version 3.20.5 if 3.21.3 is not possible.
- Use version 3.19.9 or 3.18.12 as alternatives.
- Install version 3.17.18 if older versions are necessary.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-15343.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-15343 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-15343
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-15343 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-15343 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by [email protected]
Nov. 03, 2026
Action Type Old Value New Value Changed 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. A path traversal vulnerability was identified in GitHub Enterprise Server that allowed an attacker with code execution inside a Dependabot updater container to write files to arbitrary repository paths, including GitHub Actions workflow files under .github/workflows/, because path validation did not check the actual write destination. The initial fix in versions 3.21.3, 3.20.5, 3.19.9, 3.18.12, and 3.17.18 was incomplete because validation checked the supplied symlink target, while the publisher wrote the file using its directory and name. Writing GitHub Actions workflow files required the Dependabot installation to have workflows: write permission. Depending on repository permissions and workflow configuration, including a relevant pull_request_target workflow or auto-merge, an injected workflow could execute with access to GitHub Actions secrets. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.23 and was fully fixed in versions 3.22.3, 3.21.8, 3.20.10, and 3.19.14. This vulnerability was reported via the GitHub Bug Bounty program. Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/15xxx/CVE-2026-15343.json">CVE-2026-15343</a> Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.17.18 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.18.12 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.19.14 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.19.9 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.20.10 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.20.5 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.21.3 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.21.8 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.22.3 Removed Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.17.18 Removed Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.18.12 Removed Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.19.9 Removed Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.20.5 Removed Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.21.3 -
CVE Translated by [email protected]
Oct. 24, 2026
Action Type Old Value New Value Added Translation Title: Enterprise Server de GitHub, Description: Una vulnerabilidad de salto de ruta fue identificada en GitHub Enterprise Server que permitía a un atacante que tenía ejecución de código dentro del contenedor del actualizador de Dependabot escribir archivos en rutas de repositorio arbitrarias, incluyendo archivos de flujo de trabajo de GitHub Actions bajo .github/workflows/, ya que la validación de ruta no verificaba la ruta efectiva que el atacante podía controlar a través del directorio del archivo de dependencia y el objetivo del enlace simbólico. Si el repositorio utilizaba un flujo de trabajo pull_request_target o tenía la fusión automática habilitada, un flujo de trabajo inyectado podría ejecutarse con acceso a los secretos de GitHub Actions del repositorio. Esta vulnerabilidad afectó a todas las versiones de GitHub Enterprise Server anteriores a la 3.22 y fue corregida en las versiones 3.21.3, 3.20.5, 3.19.9, 3.18.12, 3.17.18. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-15343', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-17T16:31:35.938532Z'} -
New CVE Received by [email protected]
Jul. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'GitHub', 'product': 'Enterprise Server', 'versions': [{'status': 'affected', 'changes': [{'at': '3.17.18', 'status': 'unaffected'}], 'version': '3.17.0', 'versionType': 'semver', 'lessThanOrEqual': '3.17.17'}, {'status': 'affected', 'changes': [{'at': '3.18.12', 'status': 'unaffected'}], 'version': '3.18.0', 'versionType': 'semver', 'lessThanOrEqual': '3.18.11'}, {'status': 'affected', 'changes': [{'at': '3.19.9', 'status': 'unaffected'}], 'version': '3.19.0', 'versionType': 'semver', 'lessThanOrEqual': '3.19.8'}, {'status': 'affected', 'changes': [{'at': '3.20.5', 'status': 'unaffected'}], 'version': '3.20.0', 'versionType': 'semver', 'lessThanOrEqual': '3.20.4'}, {'status': 'affected', 'changes': [{'at': '3.21.3', 'status': 'unaffected'}], 'version': '3.21.0', 'versionType': 'semver', 'lessThanOrEqual': '3.21.2'}], 'defaultStatus': 'affected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-22 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.17.18 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.18.12 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.19.9 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.20.5 Added Reference https://docs.github.com/en/[email protected]/admin/release-notes#3.21.3