title: Cross site scripting vulnerability with discussion titles in flarum
description: Flarum is an open source discussion platform. Flarum's page title system allowed for page titles to be converted into HTML DOM nodes when pages were rendered. The change was made after `v1.5` and was not noticed. This allowed an attacker to inject malicious HTML markup using a discussion title input, either by creating a new discussion or renaming one. The XSS attack occurs after a visitor opens the relevant discussion page. All communities running Flarum from `v1.5.0` to `v1.6.1` are impacted. The vulnerability has been fixed and published as flarum/core `v1.6.2`. All communities running Flarum from `v1.5.0` to `v1.6.1` have to upgrade as soon as possible to v1.6.2. There are no known workarounds for this issue.
problem types: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
affected:
{
vendor: flarum
product: framework
versions:
version: >= 1.5.0, < 1.6.2, status: affected
}
metrics:
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
attackVector: NETWORK
attackComplexity: LOW
privilegesRequired: LOW
userInteraction: REQUIRED
scope: CHANGED
confidentialityImpact: HIGH
integrityImpact: HIGH
availabilityImpact: HIGH
baseScore: 9
baseSeverity: CRITICAL
]