CVE-2026-126569

Description

Mbin 1.2.1 before 1.11.1 contains a stored cross-site scripting vulnerability in EmbedElement::buildDestructed() that renders nested Markdown image alt text and URL without HTML escaping. Authenticated users can embed HTML in the alt text of an image inside a link in entries, comments, posts, messages, or bios to run script in viewers' browsers.

References

• https://github.com/MbinOrg/mbin/blob/v1.11.0/src/Markdown/CommonMark/EmbedElement.php#L57-L67
• https://github.com/MbinOrg/mbin/commit/736fd39fe9cd59f5d51636d25e1857d88ddbd0bd
• https://github.com/MbinOrg/mbin/releases/tag/v1.11.1
• https://github.com/MbinOrg/mbin/security/advisories/GHSA-g3r9-j6w4-2257
• https://www.vulncheck.com/advisories/mbin-1.2.1-before-1.11.1-stored-xss-via-markdown-image-nested-in-link