Skip to main content
VulnerabilityPublished Updated

CVE-2025-69873: Node ajv · ajv (Another JSON Schema Validator) before 8.18.0 is vulnerable to Regular Expression

Affects node-ajvSource GCVE Database

0
Authoritative record:CVE-2025-69873· Low 2.9

Not known to be exploited · CVSS 2.9 Low · fixed in 6.14.0 : update node-ajv when convenient.

Data as of 27 Oct 2026, 06:42 UTC

CVSS 3.1 base score
2.9Low
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 6.14.0
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 11 Feb 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Ubuntu 26.10node-ajvpkg:deb/ubuntu/node-ajv?arch=source&distro=stonkingOther threatsAffected
  • 8.17.1~ds+~3.0.1+~3.1.0-4build1 – 8.20.0~ds+~cs7.1.3-3
5 affected builds
Fixed in–
Ubuntu 26.04 LTSnode-ajvpkg:deb/ubuntu/node-ajv?arch=source&distro=resoluteOther threatsAffected
  • =8.12.0~ds+~2.1.1-5
  • =8.17.1~ds+~3.0.1+~3.1.0-2
  • =8.17.1~ds+~3.0.1+~3.1.0-4build1
Fixed in–
Ubuntu 25.10node-ajvpkg:deb/ubuntu/node-ajv?arch=source&distro=questingOther threatsAffected
  • =8.12.0~ds+~2.1.1-5
Fixed in–
Ubuntu 24.04 LTSnode-ajvpkg:deb/ubuntu/node-ajv?arch=source&distro=nobleOther threatsAffected
  • =6.12.6-3
  • =8.12.0~ds+~2.1.1-4
Fixed in–
Ubuntu 22.04 LTSnode-ajvpkg:deb/ubuntu/node-ajv?arch=source&distro=jammyOther threatsAffected
  • =6.12.6-2
  • =6.12.6-3
Fixed in–
Ubuntu 20.04 LTSnode-ajvpkg:deb/ubuntu/node-ajv?arch=source&distro=focalOther threatsAffected
  • =6.10.2-1
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

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

Community reviews

Loading reviews…