CVE-20XX-?
agent?

CVE-2026-33393

4.3 MEDIUM 0.3% exploit odds Fix listed Auth & access

What it is

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.

At a glance

Exploitability
Can be exploited over the network with a low-privilege account. Limited direct impact.
Exploit odds
0.3% chance of exploitation in the next 30 days (EPSS).
Fix
A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

  1. PublishedDisclosed publicly on CVE.org and NVD
  2. Last updatedMost recent change to the record

Why it ranks here

Details

Published
Last modified
Exploit probability
0.3% · EPSS, next 30 days
Weakness
CWE-284 · Improper access control
Record status
Analyzed

Affected

Attack profile CVSS 3.1 · 4.3

Attack vector
Network
Complexity
Low
Privileges needed
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Raw vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-33393.md and follow it. Check whether this project is affected by CVE-2026-33393. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Meme: I wake up, CVE-2026-33393
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Fix and advisories

References

NVD record · CVE.org record