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Fencer Vulns
medium 5.3

CVE-2026-48125 json

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

published 2026-06-15 4 mo ago modified 2026-10-24 15 d ago also EUVD-2026-44540 , GHSA-9h5v-pfqq-x599

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

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.

Patch / fix

  • npm ua-parser-js 2.0.10
  • ua-parser-js_project ua-parser-js 2.0.10
  • node-ua-parser-js Debian 14 2.0.10+ds+~cs0.3.5-1

debian advisories DEBIAN-CVE-2026-48125

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-48125 updated cvss 5.3

ua-parser-js: UAParser.js: Denial of Service via crafted Client Hints header

  • Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9 Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-ui-rhel8 Red Hat Build of Podman Desktop rh-podman-desktop.git Red Hat Ceph Storage 9 rhceph/alloy-rhel10 Red Hat Enterprise Linux 7 rhsm-gtk, python-syspurpose, subscription-manager, subscription-manager-gui, subscription-manager-rhsm, subscription-manager-cockpit, +5 more Red Hat OpenShift Container Platform 4 openshift4/ose-console, openshift4/ose-console-rhel9
    +1 more products
    Red Hat OpenShift Container Platform 5 openshift5/ose-console-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images dotnet8.0 8.0.128-1.1.hum1 Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
npm ua-parser-js
>=2.0.1, <2.0.10
2.0.10

Affected products

  • faisalman ua-parser-js

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-1333 Inefficient Regular Expression Complexity

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.