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Case File

CVE-2026-33393

MEDIUM · CVSS 4.3 EPSS 0.25% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2026-03-19 · Last synced 2026-08-04

CyberRota Analysis

This is a medium severity vulnerability with a CVSS score of 4.3. Public exploit code or proof-of-concept references have been detected in its references.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-33393
Severity
MEDIUM
CVSS
4.3
EPSS
0.25%

Original NVD 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.

Related CVEs

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