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CVE PROGRAM SOURCE RECORD9.1 Critical

CVE-2026-21881

Kanboard is Vulnerable to Reverse Proxy Authentication Bypass

Description

Kanboard is project management software focused on Kanban methodology. Versions 1.2.48 and below is vulnerable to a critical authentication bypass when REVERSE_PROXY_AUTH is enabled. The application blindly trusts HTTP headers for user authentication without verifying the request originated from a trusted reverse proxy. An attacker can impersonate any user, including administrators, by simply sending a spoofed HTTP header. This issue is fixed in version 1.2.49.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

kanboard kanboard

  • < 1.2.49affected

References