Critical severity9.1OSV Advisory· Published Jan 8, 2026· Updated Jun 17, 2026
CVE-2026-21881
CVE-2026-21881
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.
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Affected products
3Patches
Vulnerability mechanics
References
3- github.com/kanboard/kanboard/commit/7af6143e2ad25b5c15549cca8af4341c7ac4e2fcnvdPatch
- github.com/kanboard/kanboard/security/advisories/GHSA-wwpf-3j4p-739wnvdExploitVendor Advisory
- github.com/kanboard/kanboard/releases/tag/v1.2.49nvdRelease Notes
News mentions
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