SB20261106100 - Multiple vulnerabilities in MantisBT

Description

This security bulletin contains information about 2 vulnerabilities.

1) Cross-site scripting (CVE-ID: CVE-2026-33517)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]

The vulnerability allows a remote authenticated attacker with low privileges to inject stored HTML and execute arbitrary JavaScript in a victim's browser when Content Security Policy settings permit.

The vulnerability exists due to improper escaping of tag names in MantisBT's tag_delete.php when rendering the tag deletion confirmation. A remote authenticated attacker with low privileges can store a malicious tag name that executes script when a victim opens the deletion confirmation.

2) Authentication Bypass by Primary Weakness (CVE-ID: CVE-2026-30849)

CWE-ID: CWE-305 - Authentication Bypass by Primary Weakness

CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows an unauthenticated remote attacker to bypass authentication and execute SOAP API functions with the permissions of a victim's account.

The vulnerability exists due to improper password parameter type checking in the MantisBT SOAP API when MySQL or a compatible database performs implicit string-to-integer conversion. An unauthenticated remote attacker can submit a crafted SOAP envelope containing a known victim username to authenticate without knowing the victim's password.

Remediation

Install update from vendor's website.

References

• https://github.com/mantisbt/mantisbt/security/advisories/GHSA-fh48-f69w-7vmp
• https://github.com/mantisbt/mantisbt/security/advisories/GHSA-phrq-pc6r-f6gh