Auth bypass in Discourse
CVE-2026-33408
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, moderators were able to see the first 40 characters of post edits in PMs and private categories. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 2.2 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (27.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 27.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
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-wf9r-386h-g29c (Vendor Advisory)
- github.com/discourse/discourse/commit/3bf3793a708662716c0a4eaf64ae091abe71ab4c (Patch)
- github.com/discourse/discourse/commit/473288219e93cd17576cf15e4f0b9e388a31d0c1 (Patch)
- github.com/discourse/discourse/commit/62721429d4402505d21280bcbe5894032447d800 (Patch)
Frequently asked questions
- What is CVE-2026-33408?
- CVE-2026-33408 is a low-severity vulnerability in Discourse, classified under Missing Authorization. CVSS score: 2.2/10. Published 2026-03-19.
- How severe is CVE-2026-33408?
- Low severity. CVSS v3 base score is 2.2 out of 10.