PT-2026-56893 · Discourse · Discourse

Published 2026-07-09 · Updated 2026-07-09 · CVE-2026-55420

Mitre

CVSS v3.1

7.5

High

Base vector

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

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, under certain non-default configurations, processing of PDF uploads could be exploited to obtain RCE on the server. This issue is patched in 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.

Fix

OS Command Injection

Weakness Enumeration

CWE-78

Related Identifiers

CVE-2026-55420

Affected Products

Discourse

References · 7

• https://nvd.nist.gov/vuln/detail/CVE-2026-55420 · Security Note
• https://github.com/discourse/discourse/commit/ca5a7e06167561928556afa2f237d67e459c6914 · Note
• https://github.com/discourse/discourse/releases/tag/v2026.6.0 · Note
• https://github.com/discourse/discourse/security/advisories/GHSA-7wq5-jgww-5rw3 · Note
• https://github.com/discourse/discourse/releases/tag/v2026.5.1 · Note
• https://github.com/discourse/discourse/releases/tag/v2026.4.2 · Note
• https://github.com/discourse/discourse/releases/tag/v2026.1.5 · Note