{"id":"GHSA-j535-v25q-vx3q","summary":"n8n: Regular Expression Denial of Service in the Default Blocked-File-Pattern Match via a Git Node Clone Path","details":"## Impact\n\nThe 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.\n\n## Patches\n\nThe 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.\n\n## Workarounds\n\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Restrict n8n instance access to fully trusted users only.\n- Disable the Git node by adding `n8n-nodes-base.git` to the `NODES_EXCLUDE` environment variable.\n- Set `N8N_BLOCK_FILE_PATTERNS` to a backtracking-safe equivalent pattern to replace the vulnerable default.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.","aliases":["CVE-2026-86081"],"modified":"2026-09-10T15:30:04.749866465Z","published":"2026-09-10T15:12:00Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-09-10T15:12:00Z","nvd_published_at":"2026-09-08T22:19:17Z","cwe_ids":["CWE-1333"],"severity":"HIGH"},"references":[{"type":"WEB","url":"https://github.com/n8n-io/n8n/security/advisories/GHSA-j535-v25q-vx3q"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86081"},{"type":"PACKAGE","url":"https://github.com/n8n-io/n8n"},{"type":"WEB","url":"https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.76"},{"type":"WEB","url":"https://github.com/n8n-io/n8n/releases/tag/n8n@2.37.7"},{"type":"WEB","url":"https://github.com/n8n-io/n8n/releases/tag/n8n@2.38.2"}],"affected":[{"package":{"name":"n8n","ecosystem":"npm","purl":"pkg:npm/n8n"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.123.76"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-j535-v25q-vx3q/GHSA-j535-v25q-vx3q.json"}},{"package":{"name":"n8n","ecosystem":"npm","purl":"pkg:npm/n8n"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.38.0"},{"fixed":"2.38.2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-j535-v25q-vx3q/GHSA-j535-v25q-vx3q.json"}},{"package":{"name":"n8n","ecosystem":"npm","purl":"pkg:npm/n8n"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.0.0"},{"fixed":"2.37.7"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-j535-v25q-vx3q/GHSA-j535-v25q-vx3q.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}]}