Kanboard is Vulnerable to Reverse Proxy Authentication Bypass_CVE-2026-21881

9.1 / 10

CRITICAL

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

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.

AI Analysis

Critical authentication bypass vulnerability in Kanboard when REVERSE_PROXY_AUTH is enabled, allowing attackers to impersonate users by sending spoofed HTTP headers.

Basic Information

ID CVE-2026-21881

Source GitHub_M

Published Jan 8, 2026 at 01:08

Affected Product

Vendor kanboard

Product kanboard

Version < 1.2.49

Affected Versions kanboard kanboard < 1.2.49

CWE Classification

CWE-287

AI Assessment

AI Score 9.1 / 10

AI Severity Critical

Vendor Kanboard

Product Kanboard

Version 1.2.48 and below

References

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    "published": "2026-01-08T01:08:01.853Z",
    "modified": "2026-01-08T01:08:01.853Z",
    "type": "cve",
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