CVE-2026-48125: CWE-400: Uncontrolled Resource Consumption in faisalman ua-parser-js
UAParser.js versions 2.0.1 through 2.0.9 contain a regular expression denial-of-service (ReDoS) vulnerability when processing Client Hints headers. Specifically, a crafted Sec-CH-UA-Model header can trigger excessive CPU usage due to catastrophic backtracking in the device regex. This occurs because Client Hints values are not limited by the UA_MAX_LENGTH restriction applied to User-Agent values. The issue is fixed starting in version 2.0.10.
AI Analysis
Technical Summary
The vulnerability in faisalman ua-parser-js affects versions from 2.0.1 up to but not including 2.0.10. When the library processes Client Hints headers via the withClientHints() method, an attacker can supply a malicious Sec-CH-UA-Model header that causes catastrophic backtracking in a regular expression used to parse device information. This leads to uncontrolled resource consumption (CPU exhaustion), constituting a regular expression denial-of-service (ReDoS) attack. The root cause is the absence of the UA_MAX_LENGTH limit on Client Hints values, unlike User-Agent values. The vulnerability is addressed in version 2.0.10.
Potential Impact
An attacker can cause excessive CPU consumption on a system using vulnerable versions of ua-parser-js by sending a specially crafted Sec-CH-UA-Model header. This results in a denial-of-service condition due to the regular expression's catastrophic backtracking. There is no impact on confidentiality or integrity, only availability is affected.
Mitigation Recommendations
Upgrade ua-parser-js to version 2.0.10 or later, where the vulnerability is fixed. No other mitigations are specified or required.
CVE-2026-48125: CWE-400: Uncontrolled Resource Consumption in faisalman ua-parser-js
Description
UAParser.js versions 2.0.1 through 2.0.9 contain a regular expression denial-of-service (ReDoS) vulnerability when processing Client Hints headers. Specifically, a crafted Sec-CH-UA-Model header can trigger excessive CPU usage due to catastrophic backtracking in the device regex. This occurs because Client Hints values are not limited by the UA_MAX_LENGTH restriction applied to User-Agent values. The issue is fixed starting in version 2.0.10.
CVSS v3.1
Score 5.3medium
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in faisalman ua-parser-js affects versions from 2.0.1 up to but not including 2.0.10. When the library processes Client Hints headers via the withClientHints() method, an attacker can supply a malicious Sec-CH-UA-Model header that causes catastrophic backtracking in a regular expression used to parse device information. This leads to uncontrolled resource consumption (CPU exhaustion), constituting a regular expression denial-of-service (ReDoS) attack. The root cause is the absence of the UA_MAX_LENGTH limit on Client Hints values, unlike User-Agent values. The vulnerability is addressed in version 2.0.10.
Potential Impact
An attacker can cause excessive CPU consumption on a system using vulnerable versions of ua-parser-js by sending a specially crafted Sec-CH-UA-Model header. This results in a denial-of-service condition due to the regular expression's catastrophic backtracking. There is no impact on confidentiality or integrity, only availability is affected.
Mitigation Recommendations
Upgrade ua-parser-js to version 2.0.10 or later, where the vulnerability is fixed. No other mitigations are specified or required.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-20T18:46:58.291Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a56a78f68715ace43381305
Added to database: 07/14/2026, 21:18:07 UTC
Last enriched: 07/14/2026, 21:51:42 UTC
Last updated: 07/15/2026, 03:37:14 UTC
Views: 5
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