Vulnerability Description
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, under certain non-default configurations, processing of PDF uploads could be exploited to obtain RCE on the server. This issue is patched in 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Discourse | Discourse | >= 2026.1.0, < 2026.1.5 |
Related Weaknesses (CWE)
References
- https://github.com/discourse/discourse/commit/ca5a7e06167561928556afa2f237d67e45Patch
- https://github.com/discourse/discourse/releases/tag/v2026.1.5Release Notes
- https://github.com/discourse/discourse/releases/tag/v2026.4.2Release Notes
- https://github.com/discourse/discourse/releases/tag/v2026.5.1Release Notes
- https://github.com/discourse/discourse/releases/tag/v2026.6.0Release Notes
- https://github.com/discourse/discourse/security/advisories/GHSA-7wq5-jgww-5rw3MitigationVendor Advisory
FAQ
What is CVE-2026-55420?
CVE-2026-55420 is a vulnerability with a CVSS score of 7.5 (HIGH). Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, under certain non-default configurations, processing of PDF uploads could be exploited to obtain R...
How severe is CVE-2026-55420?
CVE-2026-55420 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-55420?
Check the references section above for vendor advisories and patch information. Affected products include: Discourse Discourse.