CVE-2026-17556: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in GitHub Enterprise Server
CVE-2026-17556 is a path traversal vulnerability in GitHub Enterprise Server that allows unauthenticated attackers to delete arbitrary files and directories on the affected instance. The vulnerability exploits improper sanitization of the X-GitHub-Request-Id header, enabling deletion of critical data including user storage directories. It affects versions prior to 3.22 and was fixed in several patch releases. Exploitation requires only network access and works even in private mode.
AI Analysis
Technical Summary
This vulnerability (CWE-22) in GitHub Enterprise Server arises from the unsanitized use of the X-GitHub-Request-Id HTTP header as a filesystem path segment for the upload buffer directory. An attacker can supply a path traversal payload in this header, causing the deferred cleanup routine to recursively delete arbitrary files and directories on the server, including user storage data such as Git LFS objects, release assets, attachments, and avatars. The flaw requires no authentication and is exploitable remotely. Affected versions include 3.17.0, 3.18.0, 3.19.0, 3.20.0, and 3.21.0. The issue was fixed in versions 3.21.4, 3.20.6, 3.19.10, 3.18.13, and 3.17.19.
Potential Impact
An unauthenticated attacker with network access can delete arbitrary files and directories on the GitHub Enterprise Server instance, potentially causing data loss including user storage and repository assets. This can disrupt service availability and result in significant operational impact.
Mitigation Recommendations
A fix is available and has been released in GitHub Enterprise Server versions 3.21.4, 3.20.6, 3.19.10, 3.18.13, and 3.17.19. Users should upgrade to one of these versions or later to remediate this vulnerability. No other mitigation or workaround is indicated.
CVE-2026-17556: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in GitHub Enterprise Server
Description
CVE-2026-17556 is a path traversal vulnerability in GitHub Enterprise Server that allows unauthenticated attackers to delete arbitrary files and directories on the affected instance. The vulnerability exploits improper sanitization of the X-GitHub-Request-Id header, enabling deletion of critical data including user storage directories. It affects versions prior to 3.22 and was fixed in several patch releases. Exploitation requires only network access and works even in private mode.
CVSS v4.0
Score 8.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CWE-22) in GitHub Enterprise Server arises from the unsanitized use of the X-GitHub-Request-Id HTTP header as a filesystem path segment for the upload buffer directory. An attacker can supply a path traversal payload in this header, causing the deferred cleanup routine to recursively delete arbitrary files and directories on the server, including user storage data such as Git LFS objects, release assets, attachments, and avatars. The flaw requires no authentication and is exploitable remotely. Affected versions include 3.17.0, 3.18.0, 3.19.0, 3.20.0, and 3.21.0. The issue was fixed in versions 3.21.4, 3.20.6, 3.19.10, 3.18.13, and 3.17.19.
Potential Impact
An unauthenticated attacker with network access can delete arbitrary files and directories on the GitHub Enterprise Server instance, potentially causing data loss including user storage and repository assets. This can disrupt service availability and result in significant operational impact.
Mitigation Recommendations
A fix is available and has been released in GitHub Enterprise Server versions 3.21.4, 3.20.6, 3.19.10, 3.18.13, and 3.17.19. Users should upgrade to one of these versions or later to remediate this vulnerability. No other mitigation or workaround is indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_P
- Date Reserved
- 2026-07-27T13:19:24.539Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a739c88bf8831d5396b2ff6
Added to database: 08/05/2026, 20:26:48 UTC
Last enriched: 08/05/2026, 20:42:00 UTC
Last updated: 08/06/2026, 02:13:33 UTC
Views: 56
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