CVE-2026-89253

HIGH
Published Sep 11, 2026 Modified Sep 11, 2026 CWE-79

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.

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CVSS v3.1 Score

8.7
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0035
Probability of exploitation
0.28%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Frequently Asked Questions

What is CVE-2026-89253? +
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. It has a CVSS v3.1 base score of 8.7 (HIGH).
How severe is CVE-2026-89253? +
CVE-2026-89253 has a CVSS v3.1 score of 8.7 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0035, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-89253? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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