CVE-2026-48125: CWE-400: Uncontrolled Resource Consumption in faisalman ua-parser-js
UAParser.js versions from 2.0.1 up to but not including 2.0.10 contain a regular expression denial-of-service (ReDoS) vulnerability when using the Client Hints API. This occurs because the Sec-CH-UA-Model header is processed without length limits, leading to excessive CPU consumption due to catastrophic backtracking in the device regex. The issue is fixed in version 2.0.10.
AI Analysis
Technical Summary
The vulnerability in UAParser.js (CVE-2026-48125) affects versions >=2.0.1 and <2.0.10. When the library processes Client Hints headers via the withClientHints() method, a crafted Sec-CH-UA-Model header can trigger catastrophic backtracking in a regular expression used to parse device information. This results in uncontrolled resource consumption (CPU exhaustion), constituting a regular expression denial-of-service (ReDoS) attack. The root cause is that Client Hints values are copied without applying the UA_MAX_LENGTH limit that is used for User-Agent values. This vulnerability is resolved in version 2.0.10.
Potential Impact
An attacker can cause excessive CPU usage on an application using vulnerable UAParser.js versions by sending a specially crafted Sec-CH-UA-Model header. This leads to denial-of-service conditions due to resource exhaustion. There is no impact on confidentiality or integrity, only availability is affected.
Mitigation Recommendations
Upgrade to UAParser.js version 2.0.10 or later, where this vulnerability is fixed. Patch status is confirmed by the version range and fix version stated in the description. No other mitigations are indicated.
CVE-2026-48125: CWE-400: Uncontrolled Resource Consumption in faisalman ua-parser-js
Description
UAParser.js versions from 2.0.1 up to but not including 2.0.10 contain a regular expression denial-of-service (ReDoS) vulnerability when using the Client Hints API. This occurs because the Sec-CH-UA-Model header is processed without length limits, leading to excessive CPU consumption due to catastrophic backtracking in the device regex. The issue is fixed 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 UAParser.js (CVE-2026-48125) affects versions >=2.0.1 and <2.0.10. When the library processes Client Hints headers via the withClientHints() method, a crafted Sec-CH-UA-Model header can trigger catastrophic backtracking in a regular expression used to parse device information. This results in uncontrolled resource consumption (CPU exhaustion), constituting a regular expression denial-of-service (ReDoS) attack. The root cause is that Client Hints values are copied without applying the UA_MAX_LENGTH limit that is used for User-Agent values. This vulnerability is resolved in version 2.0.10.
Potential Impact
An attacker can cause excessive CPU usage on an application using vulnerable UAParser.js versions by sending a specially crafted Sec-CH-UA-Model header. This leads to denial-of-service conditions due to resource exhaustion. There is no impact on confidentiality or integrity, only availability is affected.
Mitigation Recommendations
Upgrade to UAParser.js version 2.0.10 or later, where this vulnerability is fixed. Patch status is confirmed by the version range and fix version stated in the description. No other mitigations are indicated.
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: 07/21/2026, 22:47:26 UTC
Last updated: 08/22/2026, 22:52:14 UTC
Views: 75
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