CVE-2025-69873

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.

CVSS v3 2.9 LOW

2.9^/10

CVSS v3 : LOW

Vector :

Exploitability : 1.4 / Impact : 1.4

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/EthanKim88/ethan-cve-disclosures/blob/main/CVE-2025-69873-ajv-ReDoS.md
https://github.com/advisories/GHSA-2g4f-4pwh-qvx6
https://github.com/ajv-validator/ajv/pull/2588
https://github.com/ajv-validator/ajv/pull/2590
https://github.com/ajv-validator/ajv/releases/tag/v6.14.0
https://github.com/github/advisory-database/pull/6991

Configurations

No configuration.

History

No history.

Information

Published : 2026-02-11 19:15

Updated : 2026-03-02 21:16

NVD link : CVE-2025-69873

Mitre link : CVE-2025-69873

CVE.ORG link : CVE-2025-69873

JSON object : View

Products Affected

No product.

CWE

CWE-1333

Inefficient Regular Expression Complexity

CWE-400

Uncontrolled Resource Consumption

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