Auth bypass in Discourse

CVE-2026-34154

Discourse is an open-source discussion platform. In versions prior to 2026.1.4, 2026.3.1, 2026.4.1 and 2026.5.0-latest.1, a vulnerability in the discourse-subscriptions plugin allows users to gain access to subscription-gated groups without completing payment. This issue has been fixed in versions 2026.1.4, 2026.3.1, 2026.4.1 and 2026.5.0-latest.1.

Vulnerability class: Broken Access Control

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.003 (17.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 17.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-34154: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

  • Discourse — versions < 2026.1.4, >= 2026.4.0-latest, < 2026.4.1, 2026.5.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-34154?
CVE-2026-34154 is a medium-severity vulnerability in Discourse, classified under Missing Authorization. CVSS score: 5.3/10. Published 2026-05-19.
How severe is CVE-2026-34154?
Medium severity. CVSS v3 base score is 5.3 out of 10.