CVE-2026-28227
Discourse Vulnerable to Unauthorized Topic Creation in Staff-Only Categories via Topic Timer publish_to_category
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 2025.12.2, 2026.1.1, 2026.2.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, TL4 users can publish topics into staff-only categories via the `publish_to_category` topic timer, bypassing authorization checks. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- discourse 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