CVE-2026-115683
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AI Threat Summary
CVE-2026-115683 is a moderate vulnerability with a CVSS score of 6.8 affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
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.
Attack Chain
Attacker scans for vulnerable versions using version banners or PoC scanners
Attacker triggers CVE-2026-115683 vulnerability with a crafted request or payload
Vulnerability exploited to perform unauthorized actions on the target system
Depending on vulnerability type, attacker achieves data access, service disruption, or code execution
MITRE ATT&CK Techniques
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params |
Remediation
Quick Facts
| CVE ID | CVE-2026-115683 |
| CVSS Score | 6.8 |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
| Published | 2026-10-30 |
| Exploited | No |
| CISA KEV | No |
| PoC | Not public |
References
- https://access.redhat.com/security/cve/CVE-2026-115683
- https://beford.net/poc/ssl_poc.html
- https://bugzilla.redhat.com/show_bug.cgi?id=2560012
- https://gitlab.gnome.org/GNOME/epiphany/-/merge_requests/224…
- https://gitlab.gnome.org/GNOME/epiphany/-/work_items/2978
- https://gitlab.gnome.org/GNOME/epiphany/-/work_items/2978