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.
CVE-2026-48125
MEDIUMPre-NVD 5.35.3—Elevated
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 70% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.3
- EG Score
- 5.3(medium)
- EG Risk
- 55(Attend)EG Risk 55/100SSVC: Attend
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity53% × 45%Exploitation40% × 40%Automatability100% × 15%Action: Remediate soon — notable exploitation risk. - EPSS
- 29.6%
- KEV
- Not listed
Published
June 15, 2026
Last Modified
July 15, 2026
Advisory Details (3)
Auto-updated Jul 15, 2026🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available
Unbounded `Sec-CH-UA-Model` parsing can trigger ReDoS in `withClientHints()` · Advisory · faisalman/ua-parser-js · GitHub
https://github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599github_release Patch Available
v2.0.10
Patch available: faisalman/ua-parser-js 2.0.10
https://github.com/faisalman/ua-parser-js/releases/tag/2.0.10github_commit Patch Available
commit 90354d345849 (faisalman/ua-parser-js)
Patch available: faisalman/ua-parser-js 2.0.10 (contains commit 90354d345849)
https://github.com/faisalman/ua-parser-js/commit/90354d3458495628b1d3ba68a9d76673e6d14fc5Vendor Advisories for CVE-2026-48125(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| ua-parser-js | — | 2.0.10 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 9× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-23 03:18 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-06-15 20:46 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-400
Frequently asked(5)
What is CVE-2026-48125?
CVE-2026-48125 is a medium vulnerability published on June 15, 2026. 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…
When was CVE-2026-48125 disclosed?
CVE-2026-48125 was first published in the National Vulnerability Database on June 15, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-48125 actively exploited?
CVE-2026-48125 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 29.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-48125?
CVE-2026-48125 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-48125?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-48125, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-48125
Is Your Infrastructure Affected by CVE-2026-48125?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.