CVE-2026-30913

flarum/nickname: Display name injection in notification emails (autolink & markdown)

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.

Affected

flarum · nicknames

CVSS v3.1 GITHUB

4.6 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

EPSS

0.30% chance of exploitation in the next 30 days, 21st percentile

Published

2026-03-09

Updated

2026-03-10

Proof-of-concept exploits (1)

• advisories/GHSA-3c4m-j3g4-hh25

References

• CVE Record
• NVD entry