Description
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, insufficient SVG sanitization in upload and user avatar handling could lead to cross-site scripting when a user visited specific URLs that are not normally part of community browsing. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
Problem types
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Product status
>= 2026.4.0-latest, < 2026.4.2
>= 2026.5.0-latest, < 2026.5.1
References
github.com/...course/security/advisories/GHSA-jmcf-3367-78vv
github.com/...ommit/3ee8343cd7f00d59d8513bee0a12e02d50bfc358
github.com/...ommit/810c2715799fd08b06fd6ffc664d9562fe9ea6ff
github.com/...ommit/92a699d89b84685b6fdd63cd0d0e371793c69dad
github.com/...ommit/b8ceb49f4ba52257be30eb3c2ce51a5bf03be5fe
github.com/discourse/discourse/releases/tag/v2026.1.5
github.com/discourse/discourse/releases/tag/v2026.4.2
github.com/discourse/discourse/releases/tag/v2026.5.1
github.com/discourse/discourse/releases/tag/v2026.6.0