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Fencer Intel
high 8.7

CVE-2026-89253 json

AVideo Stored XSS via donationLink in watch page button

published 2mo ago modified 2mo ago also EUVD-2026-76065 , GHSA-34jx-r3p9-7pp2

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository WWBN/AVideo. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
8.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

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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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
2mo ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/WWBN/AVideo/security/advisories/GHSA-34jx-r3p9-7pp2 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N
CNA 3.1 8.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • WWBN AVideo

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of WWBN/AVideo published their own advisory on GitHub. Reviewed sources take precedence over it.