CVE-2026-55420

Summary

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.

Affected Software

VendorProductVersion RangeStatus
discoursediscourse>= 2026.5.0-latest, < 2026.5.1affected
discoursediscourse>= 2026.4.0-latest, < 2026.4.2affected
discoursediscourse>= 2026.1.0-latest, < 2026.1.5affected

Weaknesses

  • CWE-78: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

References