UAParser.js: Unbounded `Sec-CH-UA-Model` parsing can trigger ReDoS in `withClientHints()`

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-48125
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-14 21:16:57 UTC
Updated2026-07-15 20:21:03 UTC
DescriptionUAParser.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.

Risk And Classification

Primary CVSS: v3.1 5.3 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS: 0.003710000 probability, percentile 0.294800000 (date 2026-07-20)

Problem Types: CWE-400 | CWE-1333 | CWE-400 CWE-400: Uncontrolled Resource Consumption | CWE-1333 CWE-1333: Inefficient Regular Expression Complexity

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
3.1CNADECLARED5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Faisalman Ua-parser-js affected >= 2.0.1, < 2.0.10 Not specified

References

ReferenceSourceLinkTags
github.com/faisalman/ua-parser-js/releases/tag/2.0.10 [email protected] github.com
github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com
github.com/faisalman/ua-parser-js/commit/90354d3458495628b1d3ba68a9d7667... [email protected] github.com
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