SB2026052157 - Inefficient regular expression complexity in UAParser.js
Published: May 21, 2026
Security Bulletin ID
SB2026052157
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Partial DoS
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Inefficient regular expression complexity (CVE-ID: CVE-2026-48125)
CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity
CVSSv4: 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:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient regular expression complexity in withClientHints() when parsing a crafted Sec-CH-UA-Model header. A remote attacker can send a specially crafted request to cause a denial of service.
Only server-side applications that call UAParser(headers).withClientHints() are vulnerable.
Remediation
Install update from vendor's website.