Description
Flarum is open-source forum software. When the flarum/nicknames extension is enabled, a registered user can set their nickname to a string that email clients interpret as a hyperlink. The nickname is inserted verbatim into plain-text notification emails, and recipients may be misled into visiting attacker-controlled domains.
References (3)
Core 3
Core References
Vendor Advisory x_refsource_confirm
https://github.com/flarum/framework/security/advisories/GHSA-3c4m-j3g4-hh25
Patch x_refsource_misc
https://github.com/flarum/nicknames/commit/4dde99729abdce8f6e2a7437c86e38735fdcca28
Release Notes x_refsource_misc
https://github.com/flarum/nicknames/releases/tag/v1.8.
Scores
CVSS v3
4.6
EPSS
0.0003
EPSS Percentile
9.6%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-79
Status
published
Published
Mar 10, 2026
Tracked Since
Mar 11, 2026