CVE-2026-25565: Wekan Authorization Bypass Vulnerability

CVE-2026-25565 Overview

CVE-2026-25565 is an authorization bypass vulnerability affecting WeKan, the open-source kanban board application. Versions prior to 8.19 contain a flaw where certain card update API paths validate only board read access rather than requiring write permission. This broken access control allows users with read-only roles to perform card updates that should require write access, potentially compromising data integrity across affected WeKan installations.

Critical Impact

Users with read-only board access can modify card data without proper authorization, undermining the role-based access control model and potentially allowing unauthorized manipulation of project data.

Affected Products

• WeKan versions prior to 8.19
• wekan_project wekan (cpe:2.3:a:wekan_project:wekan:*:*:*:*:*:*:*:*)

Discovery Timeline

• 2026-02-07 - CVE-2026-25565 published to NVD
• 2026-02-10 - Last updated in NVD database

Technical Details for CVE-2026-25565

Vulnerability Analysis

This vulnerability is classified as CWE-863 (Incorrect Authorization), which occurs when a software component performs an authorization check incorrectly, allowing unauthorized actors to access or modify resources. In WeKan's case, the API endpoints responsible for card updates fail to properly validate that the requesting user has write permissions on the board.

The vulnerability enables network-based exploitation with low attack complexity. An authenticated attacker with only read permissions can leverage this flaw to modify card content, potentially disrupting workflow management, tampering with task assignments, or manipulating project timelines. While confidentiality is not directly impacted, the integrity violations could have significant consequences for organizations relying on WeKan for project management.

Root Cause

The root cause lies in inadequate permission validation within WeKan's card update API handlers. The vulnerable code paths check whether a user has read access to a board but fail to enforce write permission requirements before processing update requests. This represents a failure to implement the principle of least privilege at the API layer.

Attack Vector

The attack vector is network-based, requiring the attacker to have valid credentials with at least read-only access to a board. The exploitation path involves:

1. Authenticating to the WeKan instance with a read-only role
2. Identifying card update API endpoints through normal application interaction or API documentation
3. Sending crafted update requests to modify cards despite lacking write permissions
4. The server processes the modification due to the flawed authorization check

Since no verified proof-of-concept code is available, the exploitation mechanism involves sending authenticated HTTP requests to the card update API endpoints. The vulnerability is straightforward to exploit once an attacker understands the API structure, as it only requires bypassing a missing permission check rather than exploiting a complex technical flaw. For technical details, refer to the VulnCheck Security Advisory.

Detection Methods for CVE-2026-25565

Indicators of Compromise

• Card modifications in audit logs attributed to users with read-only roles
• Unexpected changes to card content, assignments, or status by non-authorized users
• API access logs showing card update requests from accounts that should have read-only permissions
• Discrepancies between user role assignments and modification history

Detection Strategies

• Implement API request monitoring to correlate card update operations with user permission levels
• Review WeKan audit logs for modification events performed by users assigned read-only roles
• Deploy application-layer monitoring to detect authorization bypass patterns
• Establish baseline behavior for read-only users and alert on anomalous write operations

Monitoring Recommendations

• Enable detailed API logging to capture all card update requests with associated user context
• Configure alerts for card modifications performed by accounts in read-only groups
• Implement integrity monitoring on critical board data to detect unauthorized changes
• Regularly audit user role assignments against activity logs

How to Mitigate CVE-2026-25565

Immediate Actions Required

• Upgrade WeKan to version 8.19 or later immediately
• Review all user role assignments to ensure principle of least privilege
• Audit recent card modifications to identify any potential unauthorized changes
• Consider temporarily restricting board access to trusted users until the patch is applied

Patch Information

The WeKan project has released a fix in version 8.19. The security patch is available in commit 181f837d8cbae96bdf9dcbd31beaa3653c2c0285. This commit addresses the authorization check logic to properly validate write permissions before processing card update requests.

Organizations should prioritize this update as the vulnerability allows authenticated users to exceed their intended permissions. The patch ensures that card modification operations correctly enforce write permission requirements.

Workarounds

• Temporarily revoke board access from untrusted read-only users until patching is complete
• Implement network-level access controls to restrict API access to trusted networks
• Enable enhanced logging and manual review of card modifications during the interim period
• Consider placing WeKan behind an application proxy that can enforce additional authorization checks

# Upgrade WeKan to patched version
# Using Docker (common deployment method)
docker pull wekan/wekan:v8.19
docker-compose down
docker-compose up -d

# Verify installed version
docker exec -it wekan-app wekan --version