Auth bypass in Discourse
CVE-2026-31805
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, an authorization bypass in the poll plugin allowed authenticated users to vote on, remove votes from, or toggle the open/closed status of polls they did not have access to. By passing post_id as an array (e.g. post_id[]=&post_id[]=), the authorization check resolves to the accessible post while the poll lookup resolves to a different post's poll. This affects the vote, remove_vote, and toggle_status endpoints in DiscoursePoll::PollsController. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.002 (13.9th 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.1, >= 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, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-31805?
- CVE-2026-31805 is a medium-severity vulnerability in Discourse, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-03-20.
- How severe is CVE-2026-31805?
- Medium severity. CVSS v3 base score is 5.3 out of 10.