Critical (9.9) in discourse discourse. EPSS 0.3% chance of exploitation in the next 30 days.
Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, a hostname validation issue in FinalDestination could allow bypassing SSRF protections under certain conditions. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. No known workarounds are available.
Severity
CVSS 3.1
9.9 critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS
0.3% chance of exploitation in the next 30 days; higher than 25% of CVEs (scores of 2026-10-31)