PT-2026-26359 · Discourse · Discourse

Davidtaylorhq · Published 2026-03-19 · Updated 2026-03-27 · CVE-2026-27491

Positive Technologies (AI Summary)

CVSS v4.0

6.9

Medium

Base vector

AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA: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. A type coercion issue exists in a post actions API endpoint. This issue allowed non-staff users to issue warnings to other users, a feature normally restricted to staff. Exploitation required a logged-in attacker to send a specifically crafted request to the /post actions API endpoint. The vulnerable parameter is not specified. No data exposure or privilege escalation beyond unauthorized user warnings was possible.

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.

Exploit

Fix

Missing Authorization

Weakness Enumeration

CWE-862

Related Identifiers

BIT-DISCOURSE-2026-27491

CVE-2026-27491

GHSA-XQ37-5FVF-4M4J

Affected Products

Discourse

References · 11

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27491.json · Exploit
• https://github.com/discourse/discourse/commit/d3cb203feabc46d765ecb91f348613a2bd531b89 · Patch
• https://github.com/discourse/discourse/security/advisories/GHSA-xq37-5fvf-4m4j · Vendor Advisory
• https://github.com/discourse/discourse/commit/f5fef73827da7520efc517357bd2a6bab35d7886 · Patch
• https://github.com/discourse/discourse/commit/60a588f4da4ab0feceb2c44787d4261b4f8757be · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-27491 · Security Note
• https://osv.dev/vulnerability/BIT-discourse-2026-27491 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-27491 · Vendor Advisory
• https://twitter.com/VulmonFeeds/status/2034813410655785243 · Twitter Post
• https://twitter.com/infoflowcloud/status/2035627876800696782 · Twitter Post
• https://twitter.com/CVEnew/status/2035627057510543819 · Twitter Post