Skip to content
Noroxi
NVD / CVE Program· CNA GitHub_M

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

Noroxi assessment

Priority: Monitor (action score 28/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.36% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: go-vikunja vikunja 2.4.0.

Low priority for now. Upgrade to go-vikunja vikunja 2.4.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.1 · v3.1—No exploit Fix available
Published
Aug 28, 2026
Updated
Sep 9, 2026
EPSS
0.3% · 30th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
7.1
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-55066

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for go-vikunja records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • go-vikunja vikunja

    • < 2.4.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Gocode.vikunja.io/apifrom 0—
Gocode.vikunja.io/apibefore 2.4.02.4.0
openSUSE:Leap 16.0govulncheck-vulndbbefore 0.0.20260902T191204-160000.1.10.0.20260902T191204-160000.1.1
SUSE:Linux Enterprise Server 16.0govulncheck-vulndbbefore 0.0.20260902T191204-160000.1.10.0.20260902T191204-160000.1.1

Same product

go-vikunja: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-68582Vikunja 0.24.0 Broken Object Level Authorization via Link-Share Token
    37Monitor
  • CVE-2026-123531Vikunja 1.0.0 before 2.7.1 Pagination Limit Bypass via page=0 Parameter
    34Monitor
  • CVE-2026-91985Vikunja before 2.6.0 Privilege Escalation via Link Share Hash
    34Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-55064Aug 28, 2026 · Vikunja incomplete fix for CVE-2026-35595: Write-only user can detach shared project from parent hierarchy via parent_project_id=0
    17Monitor
  • ← EarlierCVE-2026-55065Aug 28, 2026 · Vikunja: Improper Authorization and Authorization Bypass Through User-Controlled Key in code.vikunja.io/api
    32Monitor
  • Later →CVE-2026-55067Aug 28, 2026 · Vikunja: Authenticated cross-tenant kanban-bucket relocation via `project_view_id` mass-assignment
    20Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
go-vikunja vikunja2.4.0 · descriptionVendor (CNA)
Go:code.vikunja.io/api2.4.0Package registry (OSV)
opensuse:govulncheck-vulndb0.0.20260902T191204-160000.1.1 · openSUSE:Leap 16.0Package registry (OSV)
suse:govulncheck-vulndb0.0.20260902T191204-160000.1.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-6858226 days apartVikunja 0.24.0 Broken Object Level Authorization via Link-Share Token
    37Monitor
  • CVE-2026-762169 days apartVikunja through 2.4.0 Principal-Type Confusion via LinkSharing
    30Monitor
  • CVE-2026-12352272 days apartVikunja before 2.7.1 Task Information Disclosure via Kanban Bucket Move Webhook
    28Monitor
  • CVE-2026-9198418 days apartVikunja before 2.6.0 Broken Object-Level Authorization via task-position
    21Monitor
  • CVE-2026-12350372 days apartVikunja before 2.7.1 Improper Authorization in Kanban Bucket Deletion
    21Monitor
  • CVE-2026-12351872 days apartVikunja before 2.7.1 Missing Authorization in Kanban Task-Bucket Move
    21Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-639 · Authorization Bypass Through User-Controlled Key

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

nvd-secondary

Root cause

The endpoint fetches the record by the ID sent in the request, but never checks whether the record belongs to the requesting user.

The bug in code

The whole CWE-639 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
const invoice = await Invoice.findById(req.params.id);res.json(invoice);

Fixed

ts
const invoice = await Invoice.findOne({  id: req.params.id,  ownerId: req.user.id,});if (!invoice) return res.sendStatus(404);res.json(invoice);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records