# CVE-2025-69873

## Summary

- **CVE ID:** CVE-2025-69873
- **Severity:** LOW
- **CVSS Score:** 2.9 (CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L)
- **CWE:** CWE-1333
- **Published:** Feb 11, 2026
- **Last Modified:** Sep 14, 2026

## 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.

## Affected Products

- ajv.js — ajv (0)
- ajv.js — ajv (7.0.0)
- npm — ajv (>= 7.0.0-alpha.0, < 8.18.0)
- npm — ajv (< 6.14.0)

## References

- [CNA](https://github.com/advisories/GHSA-2g4f-4pwh-qvx6)
- [CNA](https://github.com/EthanKim88/ethan-cve-disclosures/blob/main/CVE-2025-69873-ajv-ReDoS.md)
- [CNA](https://github.com/github/advisory-database/pull/6991)
- [CNA](https://github.com/ajv-validator/ajv/pull/2588)
- [CNA](https://github.com/ajv-validator/ajv/releases/tag/v6.14.0)
- [CNA](https://github.com/ajv-validator/ajv/pull/2590)
- [redhat-SADP](https://access.redhat.com/security/cve/CVE-2025-69873)
- [redhat-SADP](https://bugzilla.redhat.com/show_bug.cgi?id=2439070)
- [redhat-SADP](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-69873.json)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:13512)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:6277)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:16874)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:6309)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:9742)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:6802)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:5807)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:19712)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:15091)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:14774)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:5910)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:5907)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:10093)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:6192)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:7314)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:6568)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:6497)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:6567)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:5168)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:26214)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:26211)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:33371)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:36651)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:40118)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:40984)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:40945)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:41941)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:41944)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.50%
- **EPSS Percentile:** 41.7

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._