CVE-2026-21881— Kanboard is Vulnerable to Reverse Proxy Authentication Bypass
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I. Basic Information for CVE-2026-21881
Vulnerability Information
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Vulnerability Title
Kanboard is Vulnerable to Reverse Proxy Authentication Bypass
Source: NVD (National Vulnerability Database)
Vulnerability 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.
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Source: NVD (National Vulnerability Database)
Vulnerability Type
认证机制不恰当
Source: NVD (National Vulnerability Database)
Vulnerability Title
Kanboard 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Kanboard是Kanboard开源的一套开源的可视化任务板软件。该软件能够根据业务定制面板。 Kanboard 1.2.48及之前版本存在安全漏洞，该漏洞源于启用REVERSE_PROXY_AUTH时存在认证绕过，可能导致攻击者冒充任何用户。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
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Affected Products
II. Public POCs for CVE-2026-21881
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|---|
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- https://github.com/kanboard/kanboard/releases/tag/v1.2.49x_refsource_MISC
- https://github.com/kanboard/kanboard/security/advisories/GHSA-wwpf-3j4p-739wx_refsource_CONFIRM
- https://nvd.nist.gov/vuln/detail/CVE-2026-21881
Same Patch Batch · kanboard · 2026-01-08 · 3 CVEs total
| CVE-2026-21880 | 5.3 MEDIUM | Kanboard LDAP Injection Vulnerability can Lead to User Enumeration and Information Disclos |
| CVE-2026-21879 | 4.7 MEDIUM | Kanboard vulnerable to Open Redirect via protocol-relative URLs |
IV. Related Vulnerabilities
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Kanboard TaskCreationController::duplicateProjects() endpoin - CVE-2026-25924
Kanboard is Missing Access Control on Plugin Installation le - CVE-2026-25530
Kanboard is missing authorization check in getSwimlane API a
Same weakness: CWE-287
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