Summary
n8n: Regular Expression Denial of Service in the Default Blocked-File-Pattern Match via a Git Node Clone Path
Advisory details
Impact
The Git node's clone operation matched the destination path against the default N8N_BLOCK_FILE_PATTERNS expression, which was written so that a crafted path caused catastrophic backtracking. Evaluation runs synchronously in the main n8n process, so an authenticated user could freeze the instance for everyone with a single workflow execution and no unusual configuration. The patch rewrites the pattern so that matching is linear in the length of the path.
Patches
The issue has been fixed in n8n versions 1.123.76, 2.37.7, and 2.38.2. Users should upgrade to one of these versions or later to remediate the vulnerability.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Restrict n8n instance access to fully trusted users only.
- Disable the Git node by adding
n8n-nodes-base.gitto theNODES_EXCLUDEenvironment variable. - Set
N8N_BLOCK_FILE_PATTERNSto a backtracking-safe equivalent pattern to replace the vulnerable default.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
References
- https://github.com/advisories/GHSA-j535-v25q-vx3q
- https://github.com/n8n-io/n8n/security/advisories/GHSA-j535-v25q-vx3q
- https://nvd.nist.gov/vuln/detail/CVE-2026-86081
- https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.76
- https://github.com/n8n-io/n8n/releases/tag/n8n@2.37.7
- https://github.com/n8n-io/n8n/releases/tag/n8n@2.38.2
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