SB2026010728 - Multiple vulnerabilities in Kanboard

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Open redirect (CVE-ID: CVE-2026-21879)

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

The vulnerability exists due to improper sanitization of user-supplied data within protocol-relative URLs. 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.

2) Improper Authentication (CVE-ID: CVE-2026-21881)

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error when REVERSE_PROXY_AUTH is enabled. A remote attacker can bypass authentication process and gain unauthorized access to the application.

3) LDAP injection (CVE-ID: CVE-2026-21880)

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to improper input validation within LDAP authentication mechanism. A remote attacker can send a specially crafted LDAP query to the application, bypass authentication process and gain unauthorized access to sensitive information on the system.

Remediation

Install update from vendor's website.

References

• https://github.com/kanboard/kanboard/security/advisories/GHSA-mhv9-7m9w-7hcq
• https://github.com/kanboard/kanboard/security/advisories/GHSA-wwpf-3j4p-739w
• https://github.com/kanboard/kanboard/security/advisories/GHSA-v66r-m28r-wmq7