CVE-2024-37165: Discourse has an XSS via Onebox system

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-30 · updated 2026-06-17
Weakness: CWE-79

Description

Discourse is an open source discussion platform. Prior to 3.2.3 and 3.3.0.beta3, improperly sanitized Onebox data could lead to an XSS vulnerability in some situations. This vulnerability only affects Discourse instances which have disabled the default Content Security Policy. This vulnerability is fixed in 3.2.3 and 3.3.0.beta3.

Affected products

discourse: before 3.2.3; 3.3.0-beta1, 3.3.0-beta2 — fixed in 3.2.3

How to fix

Upgrade to a fixed version: discourse 3.2.3. Check the vendor advisory for mitigations.

References

https://github.com/discourse/discourse/commit/26aef0c288839378b9de5819e96eac8cf4ea60fd
https://github.com/discourse/discourse/commit/311b737c910cf0a69f61e1b8bc0b78374b6619d2
https://github.com/discourse/discourse/security/advisories/GHSA-cx83-5p6x-9qh9
https://github.com/discourse/discourse/commit/26aef0c288839378b9de5819e96eac8cf4ea60fd
https://github.com/discourse/discourse/commit/311b737c910cf0a69f61e1b8bc0b78374b6619d2
https://github.com/discourse/discourse/security/advisories/GHSA-cx83-5p6x-9qh9

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