Auth bypass in Discourse

CVE-2026-53960

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, hidden or otherwise unviewable first-post content was leaked as an excerpt in the publicly-served Q&A (QAPage) JSON-LD structured data, exposing it to any unauthenticated visitor and to search-engine crawlers. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.

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 (21.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 21.9% 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-2026-53960: 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 < 2026.1.6, >= 2026.5.0-latest, < 2026.5.2, >= 2026.6.0-latest, < 2026.6.1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-53960?
CVE-2026-53960 is a medium-severity vulnerability in Discourse, classified under Missing Authorization. CVSS score: 5.3/10. Published 2026-08-17.
How severe is CVE-2026-53960?
Medium severity. CVSS v3 base score is 5.3 out of 10.