VULNERABILITY INTELLIGENCE

CVE-2026-41259

CVSS score7.5 HIGH
EPSS probability0.21%
CISA KEVNot currently listed
Published2026-04-23
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Description

Mastodon is a free, open-source social network server based on ActivityPub. Prior to v4.5.9, v4.4.16, and v4.3.22, Mastodon allows restricting new user sign-up based on e-mail domain names, and performs basic validation on e-mail addresses, but fails to restrict characters that are interpreted differently by some mailing servers. This vulnerability is fixed in v4.5.9, v4.4.16, and v4.3.22.

Weakness classification

  • security-advisories@github.com: CWE-841

Primary references