CVE-2026-48125
From 2.0.1 until 2.0.10, a regular expression denial-of-service vulnerability exists when using the Client Hints API.
Does this matter?
Lower severity and a low EPSS score (0.45%). Track it; it rarely justifies an emergency change on its own.
Description
UAParser.js is a JavaScript library to detect browsers, operating systems, CPUs, and devices from user-agent data. From 2.0.1 until 2.0.10, a regular expression denial-of-service vulnerability exists when using the Client Hints API. By sending a crafted Sec-CH-UA-Model header to an application that calls UAParser(headers).withClientHints(), an attacker can cause excessive CPU time due to catastrophic backtracking in the device regex because Client Hints values are copied without the UA_MAX_LENGTH limit used for User-Agent values. This issue is fixed in version 2.0.10.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- EPSS
- 0.45% probability · 38th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400, CWE-1333
- Affected
- ua-parser-js project/ua-parser-js
- Source
- security-advisories@github.com
References
- https://github.com/faisalman/ua-parser-js/commit/90354d3458495628b1d3ba68a9d76673e6d14fc5Patch
- https://github.com/faisalman/ua-parser-js/releases/tag/2.0.10Release Notes
- https://github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599Exploit, Vendor Advisory
- https://github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599Exploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.