SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-31805

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.

HIGH 8.2EPSS 0.23%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.23%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
EPSS
0.23% probability · 14th percentile
CISA KEV
Not listed
Weakness
CWE-20, CWE-863
Affected
discourse/discourse
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.