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CVE-2026-59830

Discourse: Stored XSS via unescaped actor name in post actions

Published 21 Sep 2026Updated 21 Sep 2026

Severity: MEDIUM

5.4

CVSS Base Score

Description

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.

Affected products (1)

  • discourse discourse

Problem types

  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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