VulnerabilityDeferred

CVE-2026-30913

The nickname is inserted verbatim into plain-text notification emails, and recipients may be misled into visiting attacker-controlled domains.

MEDIUM 4.6EPSS 0.17%

Does this matter?

Lower severity and a low EPSS score (0.17%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1: 4.6 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
EPSS: 0.17% probability · 6th percentile
CISA KEV: Not listed
Weakness: CWE-79
Source: security-advisories@github.com

References

https://github.com/flarum/framework/security/advisories/GHSA-3c4m-j3g4-hh25
https://github.com/flarum/nicknames/commit/4dde99729abdce8f6e2a7437c86e38735fdcca28
https://github.com/flarum/nicknames/releases/tag/v1.8.
https://github.com/flarum/framework/security/advisories/GHSA-3c4m-j3g4-hh25

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.