---
id: CVE-2025-69873
title: >-
  ajv (Another JSON Schema Validator) before 8.18.0 is vulnerable to Regular
  Expression Denial of Service (ReDoS) when the $data option is enabled
summary: >-
  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 i…
severity: low
cvss: 2.9
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-1333
  - CWE-400
vendor: ajv.js
product: ajv
affected:
  - ajv < 6.14.0
  - ajv >= 7.0.0 < 8.17.2
published: '2026-02-11'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T13:17:29.420'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-69873'
references:
  - url: >-
      https://github.com/EthanKim88/ethan-cve-disclosures/blob/main/CVE-2025-69873-ajv-ReDoS.md
    label: cve@mitre.org
  - url: 'https://github.com/advisories/GHSA-2g4f-4pwh-qvx6'
    label: cve@mitre.org
  - url: 'https://github.com/ajv-validator/ajv/pull/2588'
    label: cve@mitre.org
  - url: 'https://github.com/ajv-validator/ajv/pull/2590'
    label: cve@mitre.org
  - url: 'https://github.com/ajv-validator/ajv/releases/tag/v6.14.0'
    label: cve@mitre.org
  - url: 'https://github.com/github/advisory-database/pull/6991'
    label: cve@mitre.org
  - url: 'https://access.redhat.com/errata/RHSA-2026:10093'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:13512'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:14774'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:15091'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:16874'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:19712'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26211'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26214'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
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    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:36651'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
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    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:40945'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:40984'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:41941'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:41944'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
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    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:5807'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:5907'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:5910'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
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    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6277'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6309'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6497'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6567'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6568'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6802'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:7314'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:9742'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2025-69873'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2439070'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-69873.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-02-12T15:13:03.482882Z'
epss: 0.005
epssPercentile: 0.40306
ingestedAt: '2026-07-01T03:50:34.375Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.