Information disclosure in Discourse
CVE-2026-33355
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the `/private-posts` endpoint did not apply post-type visibility filtering, allowing regular PM participants to see whisper posts in PM topics they had access to. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.
Vulnerability class: Information Disclosure
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (37.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 37.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.000
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
- github.com/discourse/discourse/security/advisories/GHSA-g4v5-6gfp-3hjq (Vendor Advisory)
- github.com/discourse/discourse/commit/84e5865a279716c6866e8c0648d1d8b42320603c (Patch)
- github.com/discourse/discourse/commit/d25b8ee9ee182dbb34e92b34e39878ce4d59bcdc (Patch)
- github.com/discourse/discourse/commit/d2f317271ad7638f1e2791905472ebd9370946d1 (Patch)
Frequently asked questions
- What is CVE-2026-33355?
- CVE-2026-33355 is a medium-severity vulnerability in Discourse, classified under Information Disclosure. CVSS score: 6.5/10. Published 2026-03-19.
- How severe is CVE-2026-33355?
- Medium severity. CVSS v3 base score is 6.5 out of 10.