CVE-2025-3839: Epiphany: insecure external protocol invocation in epiphany

Severity: high (CVSS 8.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-23 · updated 2026-06-17
Weakness: CWE-356

Description

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.

References

https://access.redhat.com/security/cve/CVE-2025-3839
https://bugzilla.redhat.com/show_bug.cgi?id=2361430

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