Bug 2537343

Summary:	CVE-2026-94291 epiphany: Insecure iframe framing via ephy-reader/view-source schemes allows local file exfiltration [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Mauro Matteo Cascella <mcascell>
Component:	epiphany	Assignee:	Michael Catanzaro <mcatanza>
Status:	NEW ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	high
Version:	rawhide	CC:	gecko-bugs-nobody, gnome-sig, jhorak, mcatanza, mclasen, rstrode, tpopela
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["39e9d87c-b1a9-4fe2-b6e7-29c9f8127232"]}
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Bug Blocks:	2537342

Description Mauro Matteo Cascella 2026-09-21 09:40:34 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Epiphany (GNOME Web) registers custom URI schemes (ephy-reader, view-source, ephy-webextension) without marking them as display-isolated. This allows a malicious web page to embed these schemes in iframes from an HTTP context, bypassing WebKit's normal framing security controls.

Because the ephy-reader and view-source schemes can access local content, an attacker-controlled web page can use this to exfiltrate local files from the user's system. Exploitation requires the user to visit a malicious website.

The fix (commit 25e1828903cb2419e18c437723b0f87fb5d31780) registers these schemes as display-isolated via webkit_security_manager_register_uri_scheme_as_display_isolated(), preventing web content from framing them.

Upstream issue: https://gitlab.gnome.org/GNOME/epiphany/-/work_items/2952
Upstream fix: https://gitlab.gnome.org/GNOME/epiphany/-/commit/25e1828903cb2419e18c437723b0f87fb5d31780