Vulnerability in N8n
CVE-2026-77082
n8n before 1.123.69, 2.x before 2.33.4, and 2.34.x before 2.34.1 contains a regular expression denial of service (ReDoS) vulnerability in the Filter and Switch nodes, which compile user-supplied regex patterns with new RegExp() and execute them synchronously on the worker thread without complexity validation or execution timeout. A crafted regex pattern can block the worker for an extended period per data item processed, delaying other workflow executions on the same worker.
Vulnerability class: ReDoS (Regular Expression Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.005 (38.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- N8n — versions 2.34.0
- N8n-Io N8n
Weakness classification (CWE)
References
- github.com/n8n-io/n8n/security/advisories/GHSA-q3fv-295f-qfpf (vendor-advisory, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/n8n-before-redos-via-filter-and-switch-node (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-77082?
- CVE-2026-77082 is a medium-severity vulnerability in N8n, classified under Inefficient Regular Expression Complexity. CVSS score: 4.3/10. Published 2026-08-20.
- How severe is CVE-2026-77082?
- Medium severity. CVSS v3 base score is 4.3 out of 10.