CVE-2025-69873
ajv has ReDoS when using `$data` option
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.
How to fix CVE-2025-69873
To remediate CVE-2025-69873, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 8.18.0 or later
Is CVE-2025-69873 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0
- >= 7.0.0-alpha.0, < 8.18.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P |
| osv | CVSS 3.1 | LOW2.9 | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |