CVE-2026-33393General(discourse / discourse)

LOWCVSS 4.3 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

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.

0.0/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-284

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • discourse

Threat summary

  • 1 mentions across 1 observed day

What's happening

  • Technical details provided in 1 signal
  • General: 1 classified signal
  • 1 total mentions across 1 day

Affected systems

Vendors
Products
discourse

1 version affected across 1 product

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-03-20: 1Technical Details · 2026-03-20: 103-20
Signal classification1 categories
General
1100.0%
Referenced assets1 URL
By indicator
Full discourse1 post
  • CVE@CVEnew
    General

    CVE-2026-33393 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_w… https://www.cve.org/CVERecord?id=CVE-2026-33393

    Post summary

    The excerpt identifies a coding issue in Discourse’s spam host domain check, but provides only limited technical details and no evidence of exploitation or remediation.

    00000156
    56.8K followersView on X
CPE platform detail2 entries

2 of 2 entries

PartVendorProductVersionTarget SWTarget HW
Appdiscoursediscourse---
Appdiscoursediscourse2026.3.0--

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