CVE-2026-89253 AVideo Stored XSS via donationLink in watch page button
Authenticated users can inject JavaScript via donation links, allowing attackers to execute code in victims' browsers, including administrators, when viewing videos.
- 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-2026-89253?
CVE-2026-89253 is a critical cross-site scripting vulnerability in WWBN AVideo, published on 11 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 user 'donationLink' profile field. User::setDonationLink() (objects/user.php) stores the value and save() validates it only with filter_var(..., FILTER_VALIDATE_URL), which accepts strings such as http://evil.example/"onmouseover=alert(document.domain)//, while getDonationLink() applies only strip_tags() and does not encode double quotes. plugin/CustomizeUser/actionButton.php echoes the value unencoded into an <a href="..."> attribute, and that button is included from view/modeYoutubeBottom.php on the watch page when the CustomizeUser option allowDonationLink is enabled. An authenticated user who updates their own profile via objects/userUpdate.json.php can therefore break out of the href attribute and inject an event handler that executes JavaScript in the browser of any visitor—including an administrator—who views the attacker's videos and interacts with (for example, hovers over) the donation button. The issue was unfixed at the time of reporting.
Weakness: CWE-79
Which versions are affected by CVE-2026-89253?
How do I fix CVE-2026-89253?
No fix has been published for CVE-2026-89253 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-2026-89253 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-89253 exists.
Sources
Also known as GHSA-34jx-r3p9-7pp2, GHSA-hwfm-c6x6-hx7r.