GHSA-2g4f-4pwh-qvx6

ghsaUSosv

ajv has ReDoS when using `$data` option

view advisory published 2026-02-11Licence: CC-BY-4.0

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.

01

describes (1)

Related CVEs.

IDseverity exploitable
CVE-2025-69873US——
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 runtim…
02

references

External citations — patches, advisories, analysis.

scry

Advisories like this name the exposed products attackers go after on your perimeter. See what is exposed on your perimeter with a free passive scan.

Free scan