Worker denial of service via unbounded regex evaluation
Published Aug 20, 2026 · Updated Aug 20, 2026
ReDoS in n8n before 1.123.69, 2.x before 2.33.4, and 2.34.x before 2.34.1 allows remote authenticated users to interrupt service via crafted regexes. The Filter and Switch nodes pass user-supplied patterns to new RegExp() and run them synchronously on a worker thread with no regex complexity check or execution timeout, so workflow-editing access is enough to stall a worker per item processed and delay other workflows assigned to that worker.
Summary
What happened
ReDoS in n8n before 1.123.69, 2.x before 2.33.4, and 2.34.x before 2.34.1 allows remote authenticated users to interrupt service via crafted regexes. The Filter and Switch nodes pass user-supplied patterns to new RegExp() and run them synchronously on a worker thread with no regex complexity check or execution timeout, so workflow-editing access is enough to stall a worker per item processed and delay other workflows assigned to that worker.
The record
- CVE
- CVE-2026-77082
- Published
- Aug 20, 2026
- Updated
- Aug 20, 2026
- Vendor
- n8n
- Product
- n8n
- Classifications
- CWE-1333, T1499
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 20, 2026CVE publishedPublication date reported by the CVE source.
- Aug 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <1.123.69
- Affected versionversion=0 <2.33.4
- Affected versionversion=0 <2.34.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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