What’s Vulnerable › Vulnerabilities
CVE-2026-28219: Privilege Escalation via Mass Assignment Allows Regular Users to Set Topics as Global Banners
- Severity: medium (CVSS 4.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-02-26 · updated 2026-06-17
- Weakness: CWE-915
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.
Affected products
- discourse: before 2025.12.2; from 2026.1.0 before 2026.1.1; 2026.2.0 — fixed in 2025.12.2, 2026.1.1
How to fix
Upgrade to a fixed version: discourse 2025.12.2, 2026.1.1. Check the vendor advisory for mitigations.
References
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