SB2025082007 - Multiple vulnerabilities in Six Apart Movable Type

Description

This security bulletin contains information about 2 vulnerabilities.

1) Use of Less Trusted Source (CVE-ID: CVE-2025-53522)

CWE-ID: CWE-348 - Use of Less Trusted Source

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

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to use of less trusted source. A remote attacker can send a tampered email to reset a password.

2) Open redirect (CVE-ID: CVE-2025-55706)

CWE-ID: CWE-601 - URL Redirection to Untrusted Site ('Open Redirect')

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

The vulnerability allows a remote attacker to redirect victims to arbitrary URL.

The vulnerability exists due to improper sanitization of user-supplied data. A remote attacker can create a link that leads to a trusted website, however, when clicked, redirects the victim to arbitrary domain.

Successful exploitation of this vulnerability may allow a remote attacker to perform a phishing attack and steal potentially sensitive information.

Remediation

Install update from vendor's website.

References

• https://jvn.jp/en/jp/JVN76729865/index.html
• https://movabletype.org/news/2025/08/mt-843-released.html