Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-55066— Vikunja: Cross-tenant IDOR in kanban move-task endpoint via unauthorized body task_id

Quick assessment

Affected
go-vikunja vikunja
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Vikunja 是一个开源的自托管任务管理平台。在 2.4.0 版本之前， 接口接受请求体中提供的 ，但 中的 方法仅对 URL 中的项目、视图和桶进行权限验证。随后， 调用 时并未对任务本身进行额外的权限检查，从而返回了目标任务的内容；当攻击者选择一个“已完成”桶时，还可以修改任务的完成状态。由于任务标识符是全局顺序值，经过认证的用户可以枚举跨租户的任务，并通过共用该模型的 v1 和 v2 路由修改这些任务的完成元数据。该问题已在 2.4.0 版本中修复。

CVSS 7.1 · High

Affected Version Matrix 1

VendorProduct Version RangeStatus
go-vikunja vikunja < 2.4.0 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-55066

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Vikunja: Cross-tenant IDOR in kanban move-task endpoint via unauthorized body task_id
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
通过用户控制密钥绕过授权机制
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
go-vikunja vikunja < 2.4.0 -

II. Public POCs for CVE-2026-55066

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-55066

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-55066 (2)

Vendor Pages for CVE-2026-55066 (1)

Same Patch Batch · go-vikunja · 2026-08-28 · 5 CVEs total

CVE-2026-55065 8.1 HIGH Vikunja: Improper Authorization and Authorization Bypass Through User-Controlled Key in co
CVE-2026-54766 5.3 MEDIUM Vikunja: Project duplication bypasses write-permission check on the target parent project
CVE-2026-55067 5.0 MEDIUM Vikunja: Authenticated cross-tenant kanban-bucket relocation via `project_view_id` mass-as
CVE-2026-55064 4.3 MEDIUM Vikunja incomplete fix for CVE-2026-35595: Write-only user can detach shared project from

IV. Related Vulnerabilities

Same product: vikunja
Same vendor: go-vikunja
Same weakness: CWE-639

V. Comments for CVE-2026-55066

No comments yet

Leave a comment