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Vulnerabilities

Vulnerability · CVE-2025-69873

ajv: ReDoS via $data reference

Published Feb 11, 2026 · catalog updated Sep 14, 2026 · ajv: ReDoS via $data

Check if you run it

No confirmed exploitation is on record for CVE-2025-69873. EPSS is 0.55%. Act only if a listed version of ajv: ReDoS via $data is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (ajv: ReDoS via $data).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.55%
Remediation
Advisory link
Affected products
vendor ajv.js ajv

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor ajv.js ajvversion unspecified

How to fix CVE-2025-69873

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-69873. EPSS is 0.55%. Act only if a listed version of ajv: ReDoS via $data is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-1333: Inefficient Regular Expression Complexity. EPSS 0.55%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 14, 2026 · CVE.org

    Updated

    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 craf

  2. Oct 16, 2026 · CSAF Advisories

    Detected

    A flaw was found in ajv. When the $data option is enabled, the value of the pattern keyword is passed directly to the JavaScript RegExp() constructor without sufficient validation. An attacker able to supply a malicious regular expression pattern can trigger a ReDoS (Regular Expression Denial of Service), causing the application to become unresponsive and resulting in a denial of service.

Sources

  • CSAF AdvisoriesVendor advisoryRHSA-2026:9742:CVE-2025-69873

    A flaw was found in ajv. When the $data option is enabled, the value of the pattern keyword is passed directly to the JavaScript RegExp() constructor without sufficient validation. An attacker able to supply a malicious regular expression pattern can trigger a ReDoS (Regular Expr

    security.access.redhat.com
  • CVE.orgVulnerability recordCVE-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(

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-69873

    30-day exploitation probability 0.5%

    first.org

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.