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.
References (3)
Core 3
Core References
Vendor Advisory
https://discuss.flarum.org/d/27558
Patch, Third Party Advisory
https://github.com/flarum/framework/commit/690de9ce0ffe7ac4d45b73e303f44340c3433138
Third Party Advisory
https://github.com/flarum/framework/security/advisories/GHSA-7x4w-j98p-854x
Scores
CVSS v3
9.0
EPSS
0.0110
EPSS Percentile
78.1%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
total
Details
CWE
CWE-79
Status
published
Products (2)
flarum/core
1.5.0 - 1.6.2Packagist
flarum/flarum
1.5.0 - 1.6.2
Published
Nov 19, 2022
Tracked Since
Feb 18, 2026