CVE-2026-115683
Received Received - Intake

Race Condition in Epiphany TLS Certificate Bypass

Publication date: 2026-10-30

Last updated on: 2026-10-30

Assigner: Fedora Project

Description
A race condition in Epiphany allows a malicious website to bypass the TLS/SSL certificate warning page. Epiphany registers the main-world script message handler "tlsErrorPage" so its internal TLS error page can implement "Accept Risk and Proceed". The handler was registered immediately before loading the error page, leaving a brief window where the previously loaded untrusted origin could still call window.webkit.messageHandlers.tlsErrorPage.postMessage(...). The only authorization check compares a numeric WebKit page id that increments predictably; an attacker can burst-guess ids and approve a certificate exception with no user click. If a victim visits malicious site A that redirects to site B with an invalid certificate, site A can, for a few milliseconds, disable TLS certificate error warnings for host B until Epiphany is restarted, enabling man-in-the-middle or site spoofing for that host. Upstream report: https://gitlab.gnome.org/GNOME/epiphany/-/work_items/2978 Proof of concept: https://beford.net/poc/ssl_poc.html Fix: https://gitlab.gnome.org/GNOME/epiphany/-/merge_requests/2245 (register handlers on LOAD_COMMITTED). No fixed release tagged yet; reporter and maintainer describe all current versions as affected. Maintainer notes the risky registration timing dates to commit 1da1caed (Epiphany 45.x era); before that the handlers were always registered and similarly reachable from web content.

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Meta Information

Published
2026-10-30
Last Modified
2026-10-30
Generated
2026-10-30
AI Q&A
2026-10-30
EPSS Evaluated
N/A
NVD
CVE-2026-115683
EUVD
EUVD-2026-113941

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
GNOME Epiphany 0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-367 The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

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Executive Summary

This vulnerability is a race condition in the Epiphany browser that allows a malicious website to bypass TLS/SSL certificate warnings. The browser registers a message handler for TLS errors just before loading the error page, creating a brief window where an attacker can guess predictable page IDs and approve certificate exceptions without user interaction. This enables man-in-the-middle attacks or site spoofing.

Detection Guidance

This vulnerability is specific to Epiphany browser and cannot be detected via standard network or system commands. It requires checking if Epiphany is installed and its version. Inspect Epiphany's source code or configuration for the vulnerable handler registration timing.

Impact Analysis

If you use the Epiphany browser, an attacker could trick you into visiting a malicious site that then disables certificate warnings for another site you visit. This could allow the attacker to intercept your communications or impersonate a trusted website, potentially stealing sensitive data like login credentials or personal information.

Compliance Impact

This vulnerability could lead to unauthorized interception of sensitive data, violating GDPR's data protection requirements and HIPAA's safeguards for protected health information. Organizations using Epiphany may face compliance failures due to insufficient protection against man-in-the-middle attacks.

Mitigation Strategies

Avoid using Epiphany browser until a patched version is released. If Epiphany must be used, disable JavaScript in the browser settings to reduce attack surface. Monitor GNOME Epiphany's official repository for updates and apply them once available.

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