CVE-2026-48125: UAParser.js is a JavaScript library to detect browsers, operating systems, CPUs, and devices from user-agent d

Q: How do I fix CVE-2026-48125?

ua-parser-js: upgrade to 2.0.10. Exact commands for each OS are on this page.

Q: Is CVE-2026-48125 being exploited?

CVE-2026-48125 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-48125 affect?

CVE-2026-48125 affects ua-parser-js. Severity is medium (CVSS 5.3). 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 send

Q: How urgent is CVE-2026-48125?

Priority 39/100. Public exploit reference; Remotely exploitable, no login, no user action

This week

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-48125 is a medium-severity flaw (CVSS 5.3) affecting ua-parser-js. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 Clien

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 56%)
CISA exploited list	No
Weakness	CWE-400, CWE-1333
Published	2026-07-14
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: ua-parser-js project

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-14 21:16 UTCPublished CVE record published
2026-10-24 21:10 UTCUpdated Record last modified

ua-parser-js project ua-parser-js UPGRADE

Affected: >= 2.0.1 and < 2.0.10

Fixed in: 2.0.10

Safe to downgrade to: a release before 2.0.1

1. Check installed version

npm ls ua-parser-js

2. UPGRADE to 2.0.10

npm install ua-parser-js@">=2.0.10"

3. If no update is available yet, DOWNGRADE to a release before 2.0.1

npm view ua-parser-js versions npm install ua-parser-js@"<2.0.1"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-48125?

ua-parser-js: upgrade to 2.0.10. Exact commands for each OS are on this page.

Is CVE-2026-48125 being exploited?

CVE-2026-48125 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-48125 affect?

CVE-2026-48125 affects ua-parser-js. Severity is medium (CVSS 5.3). 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 send

How urgent is CVE-2026-48125?

Priority 39/100. Public exploit reference; Remotely exploitable, no login, no user action

References

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