CVE-2026-21881

critical · 9.1

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.

9.1

CVSS

0.5%

EPSS (exploit prob.)

41st

EPSS percentile

2026-01-08

Published

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Weaknesses

CWE-287

Affected products

Vendor	Product	Affected versions
kanboard	kanboard	< 1.2.49

Check a specific version with /api/v1/cve/match.

References

https://github.com/kanboard/kanboard/commit/7af6143e2ad25b5c15549cca8af4341c7ac4e2fc
https://github.com/kanboard/kanboard/releases/tag/v1.2.49
https://github.com/kanboard/kanboard/security/advisories/GHSA-wwpf-3j4p-739w
https://github.com/kanboard/kanboard/security/advisories/GHSA-wwpf-3j4p-739w

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-21881