What is CVE-2026-30913?

CVE-2026-30913 is a medium-severity vulnerability in Flarum Nicknames, classified under Cross-site Scripting. CVSS score: 4.6/10. Published 2026-03-10.

How severe is CVE-2026-30913?

Medium severity. CVSS v3 base score is 4.6 out of 10.

XSS in Flarum Nicknames

CVE-2026-30913

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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (6.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N.

Affected products

Flarum Nicknames — versions < 1.8.3

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-30913?: CVE-2026-30913 is a medium-severity vulnerability in Flarum Nicknames, classified under Cross-site Scripting. CVSS score: 4.6/10. Published 2026-03-10.
How severe is CVE-2026-30913?: Medium severity. CVSS v3 base score is 4.6 out of 10.