Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, the group email settings test endpoint could be used to make the server initiate outbound connections to arbitrary hosts and ports. This could allow probing of internal network infrastructure. The endpoint was accessible to non-staff group owners. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.
https://github.com/discourse/discourse/security/advisories/GHSA-5976-77mj-m4h3
https://github.com/discourse/discourse/commit/e75cf456e8e318290c569bd6e8fa0f2586ffc530
Published: 2026-03-31
Updated: 2026-04-09
Base Score: 4
Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:N/A:N
Severity: Medium
Base Score: 5
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
Severity: Medium
Base Score: 5.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N
Severity: Medium
EPSS: 0.00038