What’s Vulnerable › Vulnerabilities

CVE-2026-21879: Kanboard vulnerable to Open Redirect via protocol-relative URLs

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-01-08 · updated 2026-06-17
• Weakness: CWE-601

Description

Kanboard is project management software focused on Kanban methodology. Versions 1.2.48 and below are vulnerable to an Open Redirect attack that allows malicious actors to redirect authenticated users to attacker-controlled websites. By crafting URLs such as //evil.com, attackers can bypass the filter_var($url, FILTER_VALIDATE_URL) validation check. This vulnerability could be exploited to conduct phishing attacks, steal user credentials, or distribute malware. The issue is fixed in version 1.2.49.

Affected products

• kanboard: before 1.2.49 — fixed in 1.2.49

How to fix

Upgrade to a fixed version: kanboard 1.2.49. Check the vendor advisory for mitigations.

References

• https://github.com/kanboard/kanboard/commit/93bcae03301a6d34185a8dba977417e6b3de519f
• https://github.com/kanboard/kanboard/releases/tag/v1.2.49
• https://github.com/kanboard/kanboard/security/advisories/GHSA-mhv9-7m9w-7hcq
• https://github.com/kanboard/kanboard/security/advisories/GHSA-mhv9-7m9w-7hcq

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