SB2026042390 - Improper Enforcement of Behavioral Workflow in Mastodon

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Main Vulnerability Database SB2026042390

SB2026042390 - Improper Enforcement of Behavioral Workflow in Mastodon

Published: April 23, 2026

Security Bulletin ID SB2026042390
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper Enforcement of Behavioral Workflow (CVE-ID: CVE-2026-41259)

CWE-ID: CWE-841 - Improper Enforcement of Behavioral Workflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass e-mail domain restrictions for signing up.

The vulnerability exists due to improper enforcement of behavioral workflow in e-mail address validation when processing sign-up requests. A remote attacker can use special characters in an e-mail address to bypass e-mail domain restrictions for signing up.

The issue can affect both blocked domains and allow-listed domains because some mail servers interpret certain characters differently.


Remediation

Install update from vendor's website.

References