CVE-2026-21880: Medium Severity Vulnerability in Kanboard

Kanboard is project management software focused on Kanban methodology. Versions 1.2.48 and below have an LDAP Injection vulnerability in the LDAP authentication mechanism. User-supplied input is directly substituted into LDAP search filters without proper sanitization, allowing attackers to enumerate all LDAP users, discover sensitive user attributes, and perform targeted attacks against specific accounts. This issue is fixed in version 1.2.49.

The CVSS score of this vulnerability is 5.3, classified as medium severity. It indicates a low attack complexity and no privileges are required for exploitation. Given the potential for unauthorized access to sensitive information, organizations using affected versions should consider this vulnerability a high priority.

Organizations should prioritize patching immediately. This vulnerability allows attackers to exploit the LDAP authentication mechanism without requiring any user interaction, making it a significant risk for environments reliant on LDAP for authentication.

The urgency for defenders is evident as the vulnerability affects multiple instances in environments where LDAP is implemented. Attackers may leverage this vulnerability to perform targeted attacks against specific accounts, leading to potential data breaches.

To mitigate the risk, users must upgrade to version 1.2.49, which addresses the LDAP Injection vulnerability.

Vulnerability Details

The LDAP Injection vulnerability in Kanboard allows malicious actors to exploit the authentication mechanism by submitting crafted input. This vulnerability is classified under CWE-90 (LDAP Injection) and CWE-200 (Information Exposure).

The vulnerability was published on January 8, 2026, and is present in all versions prior to 1.2.49, which has been released to address this issue. The CVSS 3.1 score is 5.3, indicating a medium severity level.

Technical Analysis

The root cause of the vulnerability is the direct substitution of user input into LDAP search filters without proper sanitization. This flaw allows attackers to craft specific queries that can expose sensitive user information.

The attack vector for this vulnerability is network-based, with low attack complexity. No privileges are required for exploitation, and user interaction is not necessary. The impact is primarily on confidentiality, with low integrity and availability impact.

Risk & Impact Analysis

Risk to organizations includes potential unauthorized access to sensitive user data and the ability for attackers to perform targeted attacks. The blast radius could be significant depending on the number of users and the sensitivity of the attributes exposed.

Organizations should schedule remediation as soon as possible, given the medium severity and the potential risk of data exposure. The urgency assessment based on the CVSS score indicates that this is a vulnerability that should be addressed in the next patch cycle.

Exploitation Status

Affected Versions

All versions prior to vendor patch 1.2.49 are affected by this vulnerability. Organizations should ensure that they are running the latest version to mitigate the risk.

Mitigation & Remediation

To remediate this vulnerability, organizations must upgrade to Kanboard version 1.2.49. If immediate patching is not feasible, consider implementing additional network controls to restrict LDAP access and sanitizing user inputs.

For continuous monitoring and validation of security controls, organizations should engage in continuous penetration testing to identify similar weaknesses.

Detection Guidance

Monitoring for unusual LDAP queries and user behavior can help detect potential exploitation attempts. Log indicators should include access patterns that deviate from norm, especially those targeting sensitive user attributes.

AppSecure Threat Intelligence Insight

The long-term significance of this vulnerability lies in its implications for user privacy and data security. As organizations increasingly rely on LDAP for authentication, vulnerabilities like this highlight the necessity for rigorous input validation and sanitization practices.

This incident reflects a broader trend where attackers are targeting authentication mechanisms. Security teams should stay vigilant and adapt their strategies to safeguard against emerging threats.

To enhance security posture, organizations are encouraged to implement a comprehensive vulnerability management program and regularly conduct security assessments.

For organizations utilizing Kanboard, understanding the implications of vulnerabilities like CVE-2026-21880 can assist in developing a more proactive security strategy.