HIGHCVE-2026-41259Published Modified CNA GitHub_M
CVE-2026-41259: Mastodon: Insufficient verification of email addresses
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.
Metrics
- CVSS v4.0
- 8.2
- Severity
- HIGH
- Fixed in
- —
- Affected Products
- 1
Affected packages
- mastodon / mastodon< 4.3.22 · >= 4.4.0-beta.1, < 4.4.16 · >= 4.5.0-beta.1, < 4.5.9
CVSS Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N