CVE-2026-21881

CRITICAL
2026-01-08 [email protected]
9.1
CVSS 3.1
Share

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

Lifecycle Timeline

4
Analysis Generated
Mar 12, 2026 - 21:54 vuln.today
PoC Detected
Jan 20, 2026 - 15:57 vuln.today
Public exploit code
Patch Released
Jan 20, 2026 - 15:57 nvd
Patch available
CVE Published
Jan 08, 2026 - 02:15 nvd
CRITICAL 9.1

Tags

Authentication Bypass Kanboard

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.

Analysis

Kanboard project management (through 1.2.48) has an authentication bypass when REVERSE_PROXY_AUTH is enabled. The application trusts HTTP headers for authentication without verifying the request came from the reverse proxy. …

Sign in for full analysis, threat intelligence, and remediation guidance.

Remediation

Within 24 hours: Identify all affected systems and apply vendor patches immediately. Audit authentication configurations and rotate any potentially compromised credentials.

Sign in for detailed remediation steps.

Full analysis requires sign-in

Get intelligence summaries, risk assessment, exploit details, threat intel, and remediation guidance.

Sign in - Free

Priority Score

66
Low Medium High Critical
KEV: 0
EPSS: +0.3
CVSS: +46
POC: +20

Share

CVE-2026-21881 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy