CVE-2026-30913: flarum/nicknames extension has display name injection in notification emails (autolink & markdown)

March 10, 2026

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

github.com/advisories/GHSA-3c4m-j3g4-hh25
github.com/flarum/framework
github.com/flarum/framework/security/advisories/GHSA-3c4m-j3g4-hh25
github.com/flarum/nicknames/commit/4dde99729abdce8f6e2a7437c86e38735fdcca28
github.com/flarum/nicknames/releases/tag/v1.8.3
nvd.nist.gov/vuln/detail/CVE-2026-30913

Code Behaviors & Features

Detect and mitigate CVE-2026-30913 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →