CVE-2026-55420

Discourse: Remote code execution via pdf uploads

CVSS 7.5 HIGHCWE-78

Vexday Risk Score

18Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 7.5EPSS —KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

09 Jul 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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.

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

Affected products

discourse · discourse

References

https://github.com/discourse/discourse/commit/ca5a7e06167561928556afa2f237d67e459c6914 https://github.com/discourse/discourse/releases/tag/v2026.1.5 https://github.com/discourse/discourse/releases/tag/v2026.4.2 https://github.com/discourse/discourse/releases/tag/v2026.5.1 https://github.com/discourse/discourse/releases/tag/v2026.6.0 https://github.com/discourse/discourse/security/advisories/GHSA-7wq5-jgww-5rw3