CVE-2026-104466 YesWiki before 4.6.7 Stored XSS via Wakka Markdown Image src Attribute
Attackers can inject JavaScript via markdown image URLs in YesWiki, potentially executing code in administrators' browsers.
- 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-2026-104466?
CVE-2026-104466 is a medium-severity cross-site scripting vulnerability in yeswiki, published on 2 Oct 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
YesWiki before 4.6.7 contains a stored cross-site scripting vulnerability in formatters/wakka.php that allows users who can edit pages or post comments to inject event handlers by placing quotes in markdown image URLs. Attackers can store a crafted markdown image whose src breaks out of the attribute to add an onerror handler, executing JavaScript in viewers' browsers, including administrators.
Weakness: CWE-79
Which versions are affected by CVE-2026-104466?
How do I fix CVE-2026-104466?
No fix has been published for CVE-2026-104466 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-2026-104466 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-104466 exists.
Sources
Also known as GHSA-7pv9-pwm8-cwwr, GHSA-jjg5-rgm8-pvxr.