CVE-2026-55066

Vikunja: Cross-tenant IDOR in kanban move-task endpoint via unauthorized body task_id

HIGH
7.1
CVSS Score
Published: August 28, 2026 at 04:51 PM UTC
Updated: September 9, 2026 at 09:27 PM UTC
1 product affected across 1 vendorVikunja

Using vikunja by go-vikunja?

Get instant alerts when new vulnerabilities affect vikunja - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.1
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

Description

Vikunja is an open-source self-hosted task management platform. Prior to 2.4.0, POST /api/v1/projects/{project}/views/{view}/buckets/{bucket}/tasks accepts a body supplied task_id but TaskBucket.CanUpdate in pkg/models/kanban_task_bucket.go authorizes only the project, view, and bucket from the URL. updateTaskBucket then calls Task.ReadOne without a separate task permission check, returns the victim task contents, and can update the task done state when the attacker chooses a done bucket. Because task identifiers are global sequential values, an authenticated user can enumerate cross-tenant tasks and modify their completion metadata through both the v1 and v2 routes that share this model. This issue is fixed in version 2.4.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.4.0
Affected range stops below 2.4.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.1HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-639

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card