Discourse: Topic featured link susceptible to stored XSS
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.4epss 0.3%
exploitation probability
0.3%top 78% of all CVEs
observed exploitation
nono source reports it
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a topic "featured link" was not sufficiently normalized and escaped before being rendered in the topic list, allowing a user who can set a featured link to inject JavaScript when default Content Security Policy protections were modified or disabled. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Affected products
discourse · discourseReferences
https://github.com/discourse/discourse/commit/1bce8881e4253d9bbab56f011a12ef899b926b59https://github.com/discourse/discourse/commit/6679d9a5083488bae10c2adbb345c481c583242chttps://github.com/discourse/discourse/commit/6828aee9b15c2655d63b515ac919830bd540ff83https://github.com/discourse/discourse/commit/c9b9405f5bd0bf0269e505e28e3aad388d7657c5https://github.com/discourse/discourse/releases/tag/v2026.1.5https://github.com/discourse/discourse/releases/tag/v2026.4.2https://github.com/discourse/discourse/releases/tag/v2026.5.1https://github.com/discourse/discourse/releases/tag/v2026.6.0https://github.com/discourse/discourse/security/advisories/GHSA-695w-7fv8-mxg3