title: Discourse allows self-XSS through malicious composer message
description: Discourse is an open-source messaging platform. In versions 2.8.10 and prior on the `stable` branch and versions 2.9.0.beta11 and prior on the `beta` and `tests-passed` branches, users composing malicious messages and navigating to drafts page could self-XSS. This vulnerability can lead to a full XSS on sites which have modified or disabled Discourse’s default Content Security Policy. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.
problem types: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
affected:
{
vendor: discourse
product: discourse
versions:
version: <= 2.8.10, status: affected
version: >= 2.9.0.beta1, <= 2.9.0.beta11, status: affected
}
metrics:
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
attackVector: NETWORK
attackComplexity: HIGH
privilegesRequired: LOW
userInteraction: REQUIRED
scope: UNCHANGED
confidentialityImpact: HIGH
integrityImpact: HIGH
availabilityImpact: HIGH
baseScore: 7.1
baseSeverity: HIGH
]