Description
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the `allowed_spam_host_domains` check used `String#end_with?` without domain boundary validation, allowing domains like `attacker-example.com` to bypass spam protection when `example.com` was allowlisted. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 require exact match or proper subdomain match (preceded by `.`) to prevent suffix-based bypass of `newuser_spam_host_threshold`. No known workarounds are available.
CVSS Metrics
- Vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- Attack Vector
- network
- Complexity
- low
- Privileges
- low
- User Action
- none
- Scope
- unchanged
- Confidentiality
- none
- Integrity
- low
- Availability
- none
- Weaknesses
- CWE-284
Metadata
- Primary Vendor
- DISCOURSE
- Published
- 3/19/2026
- Last Modified
- 3/24/2026
- Source
- NIST NVD
- Note: Verify all details with official vendor sources before applying patches.
Affected Products
discourse : discoursediscourse : discoursediscourse : discourse
AI-Powered Remediation
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