CVE-2026-33500: medium-severity vulnerability in WWBN AVideo
AVideo Vulnerable to Stored XSS via Markdown `javascript:` URI Bypasses ParsedownSafeWithLinks Sanitization
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.4epss 0.2%
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Affected products
WWBN · AVideoRelated CVEs — WWBN AVideo
In the same product, most dangerous first.
CVE-2022-30690CRITICALCVE-2022-30690EPSS 83.9%CVE-2022-30534CRITICALCVE-2022-30534EPSS 75.0%CVE-2022-30547CRITICALCVE-2022-30547EPSS 63.7%CVE-2022-32572CRITICALCVE-2022-32572EPSS 24.1%CVE-2026-33478CRITICALAVideo Multi-Chain Attack: Unauthenticated Remote Code Execution via Clone Key Disclosure, Database Dump, and Command InjectionEPSS 13.3%CVE-2023-32073HIGHAVideo command injection vulnerabilityEPSS 6.5%