CVE-2026-88866 WWBN AVideo LoginControl Stored XSS via User-Agent Header
Authenticated attackers can inject scripts via User-Agent headers that execute in administrator browsers, potentially leading to session hijacking.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-88866?
CVE-2026-88866 is a critical cross-site scripting vulnerability in WWBN AVideo, published on 10 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
WWBN AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the LoginControl plugin that fails to encode the User-Agent header before storing it in login history. Attackers with any valid login account can inject malicious scripts in the User-Agent header that execute in administrator browsers when viewing the Login History page, allowing script execution within the administrator session.
Weakness: CWE-79
Which versions are affected by CVE-2026-88866?
How do I fix CVE-2026-88866?
No fix has been published for CVE-2026-88866 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-88866 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-88866 exists.
Sources
Also known as GHSA-6x7h-26ww-h8x2, GHSA-wg67-62q3-2m33.