CVE-2025-69873
Severity CVSS v4.0:
Pending analysis
Type:
CWE-400
Uncontrolled Resource Consumption ('Resource Exhaustion')
Publication date:
11/02/2026
Last modified:
12/02/2026
Description
ajv (Another JSON Schema Validator) through version 8.17.1 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.
Impact
Base Score 3.x
7.50
Severity 3.x
HIGH