Mastodon: Insufficient verification of email addresses_CVE-2026-41259

8.2 / 10

HIGH

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

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.

Basic Information

ID CVE-2026-41259

Source GitHub_M

Published Apr 23, 2026 at 18:55

Modified Apr 23, 2026 at 19:24

Affected Product

Vendor mastodon

Product mastodon

Version < 4.3.22

Affected Versions mastodon mastodon < 4.3.22
mastodon mastodon >= 4.4.0-beta.1, < 4.4.16
mastodon mastodon >= 4.5.0-beta.1, < 4.5.9

CWE Classification

CWE-841

References

github.com /mastodon/mastodon/security/advisories/GHSA-5r37-qpwq-2jhh

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