CVE-2026-33500

Sažetak

WWBN AVideo is an open source video platform. In versions up to and including 26.0, the fix for CVE-2026-27568 (GHSA-rcqw-6466-3mv7) introduced a custom `ParsedownSafeWithLinks` class that sanitizes raw HTML `<a>` and `<img>` tags in comments, but explicitly disables Parsedown's `safeMode`. This creates a bypass: markdown link syntax `[text](javascript:alert(1))` is processed by Parsedown's `inlineLink()` method, which does not go through the custom `sanitizeATag()` sanitization (that only handles raw HTML tags). With `safeMode` disabled, Parsedown's built-in `javascript:` URI filtering (`sanitiseElement()`/`filterUnsafeUrlInAttribute()`) is also inactive. An attacker can inject stored XSS via comment markdown links. Commit 3ae02fa240939dbefc5949d64f05790fd25d728d contains a patch.

Reference

CVSS

Base:	5.4
Impact:	2.7
Exploitability:	2.3

Pristup

Vektor	Složenost	Autentikacija
NETWORK	LOW	LOW

Impact

Povjerljivost	Cjelovitost	Dostupnost
LOW	LOW	NONE

CVSS vektor

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

Zadnje važnije ažuriranje

24-03-2026 - 18:11

Objavljeno

23-03-2026 - 17:16