PT-2026-26360 · Discourse · Discourse

Nlgbao1340 · Published 2026-03-19 · Updated 2026-03-22 · CVE-2026-27570

Positive Technologies · (AI Summary)

CVSS v3.1

6.1

Medium

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

Name of the Vulnerable Software and Affected Versions Discourse versions prior to 2026.3.0-latest.1 Discourse versions prior to 2026.2.1 Discourse versions prior to 2026.1.2

Description Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the onebox method in the SharedAiConversation model renders the conversation title directly into HTML without proper sanitization. This could allow for potential issues related to the display of conversation titles.

Recommendations Update Discourse to version 2026.3.0-latest.1 or later. Update Discourse to version 2026.2.1 or later. Update Discourse to version 2026.1.2 or later. As a workaround, tighten access by changing the ai bot public sharing allowed groups site setting.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-27570

Affected Products

Discourse

References · 7

• https://github.com/discourse/discourse/security/advisories/GHSA-hfxw-89hw-vwmv · Vendor Advisory
• https://github.com/discourse/discourse/commit/f2aafa5c7467c94fcd4ebd36785a98e77ca088cc · Patch
• https://github.com/discourse/discourse/commit/c14f8f52b7999328bd9f8665f2ecfa24dadc4bf1 · Patch
• https://github.com/discourse/discourse/commit/43a5a60b595f0120e6adfc131f2408508fe341f1 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-27570 · Security Note
• https://twitter.com/infoflowcloud/status/2035627920090099754 · Twitter Post
• https://twitter.com/CVEnew/status/2035627056558391407 · Twitter Post