BIT-mastodon-2026-41259

vendorUSosv

Mastodon: Insufficient verification of email addresses

view advisory published 2026-04-27Licence: per source

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.

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describes (1)

Related CVEs.

IDseverity exploitable
CVE-2026-41259UShigh7.5—
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 doma…
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