Resource exhaustion in Faisalman Ua-Parser-Js
CVE-2026-48125
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.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.004 (36.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Faisalman Ua-parser-js — versions >= 2.0.1, < 2.0.10
- Ua-parser-js_project Ua-parser-js
Weakness classification (CWE)
References
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-48125?
- CVE-2026-48125 is a medium-severity vulnerability in Faisalman Ua-Parser-Js, classified under Uncontrolled Resource Consumption. CVSS score: 5.3/10. Published 2026-07-14.
- How severe is CVE-2026-48125?
- Medium severity. CVSS v3 base score is 5.3 out of 10.