---
id: CVE-2026-115683
title: >-
  epiphany: TLS certificate warning bypass via race in tlsErrorPage message
  handler
summary: >-
  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 an…
severity: medium
cvss: 6.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N'
cvssSource: cna
cwe:
  - CWE-367
vendor: GNOME
product: epiphany
affected:
  - epiphany < 51.1
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-30T14:07:43.922960Z'
exploitAvailable: true
published: '2026-10-30'
updated: '2026-11-02'
sourceUpdated: '2026-11-02T11:33:33.900Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-115683'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-115683'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2560012'
    label: RHBZ#2560012
  - url: 'https://gitlab.gnome.org/GNOME/epiphany/-/work_items/2978'
  - url: 'https://gitlab.gnome.org/GNOME/epiphany/-/merge_requests/2245'
  - url: 'https://beford.net/poc/ssl_poc.html'
tags:
  - cve.org
  - exploit-available
epss: 0.0022
epssPercentile: 0.12704
ingestedAt: '2026-11-05T19:30:42.632Z'
---

## Overview

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.

## Affected

- `epiphany < 51.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

### Workarounds

Until a fixed Epiphany build is installed, avoid following links from untrusted sites to HTTPS destinations, and do not rely on Epiphany for sensitive sites when browsing untrusted content. Restrict network access for untrusted browsing where practical (https://cmetaxonomy.org/entries/CME-203.html). Restarting the browser clears any attacker-installed certificate exceptions for the session.