CVE-2026-86081: n8n: Regular Expression Denial of Service in the Default Blocked-File-Pattern Match via a Git Node Clone Path
Impact
The Git node's clone operation matched the destination path against the default N8NBLOCKFILEPATTERNS 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.git to the NODESEXCLUDE environment variable. - Set N8NBLOCKFILEPATTERNS to 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.
Other sources
n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the Git node clone operation matched an attacker-controlled destination path against the default N8NBLOCKFILEPATTERNS regular expression. The pattern ^(./).git(/.)$ allowed catastrophic backtracking and ran synchronously in the main n8n process. An authenticated workflow editor could therefore freeze the instance with one workflow execution; the affected default is declared in packages/@n8n/config/src/configs/security.config.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.37.7 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.38.2 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 1.123.76 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 1.123.76 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.37.7 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.38.2 - Configuration
Temporarily disable the Git node by adding `n8n-nodes-base.git` to the `NODES_EXCLUDE` environment variable.
n8n Git node NODES_EXCLUDE = n8n-nodes-base.git - Configuration
Temporarily mitigate by setting `N8N_BLOCK_FILE_PATTERNS` to a backtracking-safe equivalent pattern to replace the vulnerable default (the vulnerable pattern example was `^(./).git(/.)$`).
n8n N8N_BLOCK_FILE_PATTERNS = backtracking-safe equivalent pattern (replace vulnerable default) - Compensating control
Restrict n8n instance access to fully trusted users only (temporary mitigation).
Event History
Frequently Asked Questions
Who can exploit this issue?
An authenticated user with permission to edit workflows can exploit it by executing a workflow that uses the Git node clone operation with an attacker-controlled destination path.
Are default configurations affected?
Yes. The vulnerable regular expression is part of the default N8N_BLOCK_FILE_PATTERNS configuration.
What is the impact of successful exploitation?
The regular-expression match runs synchronously in the main n8n process and can freeze the n8n instance with a single workflow execution.
Which versions contain the fix?
The issue is fixed in n8n versions 1.123.76, 2.37.7, and 2.38.2.