epiphany: TLS certificate warning bypass via race in tlsErrorPage message handler
Impact
Epiphany is vulnerable to a TLS certificate warning bypass via a race condition in the tlsErrorPage message handler, allowing a malicious website to disable certificate error warnings. The vulnerability affects all current versions of Epiphany. An attacker can exploit this weakness by bursting guesses of predictable WebKit page IDs.
Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.What to do
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.
Affected packages
Affected products
Vendor version evidence. Product records are separate from automatic dependency matching.
GNOME · fedora
Epiphany
1 range
GNOME · fedora
Epiphany
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affected
0 → before *
semver versions
Other versions: unaffected
Original source 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.
Inside the record
Evidence available
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Original records
CVE-2026-115683View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.
cve.new JSON →Underlying weaknesses
The source’s classification of what caused the vulnerability.
Contributing organizations · 2
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Additional data publisher
What changed
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