What is CVE-2026-33425?

CVE-2026-33425 is a medium-severity vulnerability in Discourse, classified under Observable Discrepancy. CVSS score: 5.3/10. Published 2026-03-21.

How severe is CVE-2026-33425?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Auth bypass in Discourse

CVE-2026-33425

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, unauthenticated users can determine whether a specific user is a member of a private group by observing changes in directory results when using the `exclude_groups` parameter. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, disable public access to the user directory via Admin → Settings → hide user profiles from public.

EPSS: 0.002 (11.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Discourse — versions = 2026.3.0-latest, >= 2026.2.0-latest, < 2026.2.1, >= 2026.1.0-latest, < 2026.1.2

Weakness classification (CWE)

References

security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-33425?: CVE-2026-33425 is a medium-severity vulnerability in Discourse, classified under Observable Discrepancy. CVSS score: 5.3/10. Published 2026-03-21.
How severe is CVE-2026-33425?: Medium severity. CVSS v3 base score is 5.3 out of 10.