CVE-2025-3839

CVE-2025-3839

A flaw was found in Epiphany, a tool that allows websites to open external URL handler applications with minimal user interaction. This design can be misused to exploit vulnerabilities within those handlers, making them appear remotely exploitable. The browser fails to properly warn or gate this action, resulting in potential code execution on the client device via trusted UI behavior.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (32.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 32.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-3839: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: -0.000

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-3839?
CVE-2025-3839 is a high-severity vulnerability, classified under CWE-356. CVSS score: 8.0/10. Published 2026-01-23.
How severe is CVE-2025-3839?
High severity. CVSS v3 base score is 8.0 out of 10.