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VULNERABILITIES

CVE-2026-41259 Details

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.

Metrics

CVSS 3.x Severity and Vector Strings:

NIST: [email protected]CVSS-B:7.5 HIGHVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://github.com/mastodon/mastodon/security/advisories/GHSA-5r37-qpwq-2jhh [email protected]Vendor Advisory

Weakness Enumeration

CWE-IDCWE NameSource
CWE-841Improper Enforcement of Behavioral Workflow[email protected]

Affected Products

ProductVersions
joinmastodon mastodon
< 4.3.22
>= 4.4.0, < 4.4.16
>= 4.5.0, < 4.5.9

CPE

  • cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*

Remediation

  • No remediation found in references.

Change History

4 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-41259
NVD Published Date:
Apr 23, 2026
NVD Last Modified:
Jun 17, 2026
Source:
[email protected]
CVE-2026-41259 Details - Not Deferred