CVE-2026-59830

5.4 mediumEPSS 0.3%

Medium (5.4). EPSS 0.3% chance of exploitation in the next 30 days.

Discourse is an open-source discussion platform. Prior to 2026.7.0, the post action component failed to escape user-controlled display names before interpolating them into an HTML string passed to trustHTML. A user who could choose a crafted display name could persist markup in post action descriptions. Viewing the affected user activity streams could execute attacker-controlled script in another user's browser. This issue is fixed in version 2026.7.0.

Severity

CVSS 3.1

5.4 medium

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS: 0.3% chance of exploitation in the next 30 days; higher than 21% of CVEs (scores of 2026-10-31)
CWE: CWE-79
Published: 2026-09-21
Modified: 2026-09-23
Record from: the NVD, synced 2026-10-19

References

https://github.com/discourse/discourse/commit/dd786594ddd088657a7e6f9fefba5bd889965fe4
https://github.com/discourse/discourse/releases/tag/v2026.7.0
https://github.com/discourse/discourse/security/advisories/GHSA-x6mf-p7cg-69rw

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