CVE-2025-69873

Description

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.

References

https://github.com/advisories/GHSA-2g4f-4pwh-qvx6

https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-69873.json

https://github.com/github/advisory-database/pull/6991

https://github.com/ajv-validator/ajv/releases/tag/v6.14.0

https://github.com/ajv-validator/ajv/pull/2590

https://github.com/ajv-validator/ajv/pull/2588

https://github.com/EthanKim88/ethan-cve-disclosures/blob/main/CVE-2025-69873-ajv-ReDoS.md

https://bugzilla.redhat.com/show_bug.cgi?id=2439070

https://access.redhat.com/security/cve/CVE-2025-69873

https://access.redhat.com/errata/RHSA-2026:9742

https://access.redhat.com/errata/RHSA-2026:7314

https://access.redhat.com/errata/RHSA-2026:6802

https://access.redhat.com/errata/RHSA-2026:6568

https://access.redhat.com/errata/RHSA-2026:6567

https://access.redhat.com/errata/RHSA-2026:6497

https://access.redhat.com/errata/RHSA-2026:6309

https://access.redhat.com/errata/RHSA-2026:6277

https://access.redhat.com/errata/RHSA-2026:6192

https://access.redhat.com/errata/RHSA-2026:5910

https://access.redhat.com/errata/RHSA-2026:5907

https://access.redhat.com/errata/RHSA-2026:5807

https://access.redhat.com/errata/RHSA-2026:5168

https://access.redhat.com/errata/RHSA-2026:36651

https://access.redhat.com/errata/RHSA-2026:33371

https://access.redhat.com/errata/RHSA-2026:26214

https://access.redhat.com/errata/RHSA-2026:26211

https://access.redhat.com/errata/RHSA-2026:19712

https://access.redhat.com/errata/RHSA-2026:16874

https://access.redhat.com/errata/RHSA-2026:15091

https://access.redhat.com/errata/RHSA-2026:14774

https://access.redhat.com/errata/RHSA-2026:13512

https://access.redhat.com/errata/RHSA-2026:10093

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS