CVE-2025-69873

ajv (Another JSON Schema Validator) before 8.18.0 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to the JavaScript RegExp() constructor without validation. An attacker can inject a malicious regex pattern (e.g., "^(a|a)*$") combined with crafted input to cause catastrophic backtracking. A 31-character payload causes approximately 44 seconds of CPU blocking, with each additional character doubling execution time. This enables complete denial of service with a single HTTP request against any API using ajv with $data: true for dynamic schema validation. This issue is also fixed in version 6.14.0.

Score
CVSS 3.1 7.5 High
Status
Deferred - cve@mitre.org
Published
2026-02-11
Last modified
2026-09-14
Weaknesses
CWE-1333, CWE-400

Affected products

References

 
 
© AVABIS GmbH privacypolicy about