CVE-2026-41259

HIGH EPSS 11.6%
Published Apr 23, 20262mo ago · Modified Jun 17, 20261w ago
8.2 CVSS 4.0
High
Find Similar
Published Apr 23, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
8.2
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
11.6% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-841

Affected Products 3

VendorProductVersionRange
joinmastodonmastodon* <4.3.22
joinmastodonmastodon*≥4.4.0  –  <4.4.16
joinmastodonmastodon*≥4.5.0  –  <4.5.9

References 1

  • github.com https://github.com/mastodon/mastodon/security/advisories/GHSA-5r37-qpwq-2jhh
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.