What’s Vulnerable › Vulnerabilities

CVE-2025-52576: Kanboard vulnerable to Username Enumeration via Login Behavior and Bruteforce Protection Bypass

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-06-25 · updated 2026-06-17
• Weakness: CWE-203

Description

Kanboard is project management software that focuses on the Kanban methodology. Prior to version 1.2.46, Kanboard is vulnerable to username enumeration and IP spoofing-based brute-force protection bypass. By analyzing login behavior and abusing trusted HTTP headers, an attacker can determine valid usernames and circumvent rate-limiting or blocking mechanisms. Any organization running a publicly accessible Kanboard instance is affected, especially if relying on IP-based protections like Fail2Ban or CAPTCHA for login rate-limiting. Attackers with access to the login page can exploit this flaw to enumerate valid usernames and bypass IP-based blocking mechanisms, putting all user accounts at higher risk of brute-force or credential stuffing attacks. Version 1.2.46 contains a patch for the issue.

Affected products

• kanboard: before 1.2.46 — fixed in 1.2.46

How to fix

Upgrade to a fixed version: kanboard 1.2.46. Check the vendor advisory for mitigations.

References

• https://github.com/kanboard/kanboard/blob/cbb7e60fb595ff4572bb8801b275a0b451c4bda0/app/Model/UserLockingModel.php#L101-L104
• https://github.com/kanboard/kanboard/blob/cbb7e60fb595ff4572bb8801b275a0b451c4bda0/app/Subscriber/AuthSubscriber.php#L96-L108
• https://github.com/kanboard/kanboard/commit/3079623640dc39f9c7b0c840d2a79095331051f1
• https://github.com/kanboard/kanboard/security/advisories/GHSA-qw57-7cx6-wvp7
• https://github.com/kanboard/kanboard/security/advisories/GHSA-qw57-7cx6-wvp7

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