CVE-2026-55067 — Vikunja: Authenticated cross-tenant kanban-bucket relocation via `project_view_id` mass-assignment
Vikunja is an open-source self-hosted task management platform. Prior to 2.4.0, POST /api/v1/projects/{project}/views/{view}/buckets/{bucket} allows the request body project_view_id value to be mass assigned by Bucket.Update in pkg/models/kanban.go. The permission check validates that the bucket currently belongs to the URL project and view but does not validate the body selected destination view, allowing any authenticated user to relocate an attacker-owned bucket into another tenant’s Kanban view. The injected bucket retains attacker-controlled content and ownership, enabling cross-tenant defacement. This issue is fixed in version 2.4.0.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (medium)+3
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Go-vikunja Vikunja).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Go-vikunja | Vikunja | version < 2.4.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.0 | CVSS 3.1 | Medium | 3.1 | 1.4 | security-advisories@github.com via NIST National Vulnerability Database |
| 5.0 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CWE-639 · Authorization Bypass Through User-Controlled Key (IDOR)
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Audit administrative actions and access to resources outside each user’s normal pattern.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · go-vikunja/vikunja
- SSVC assessment updated
- Record published
- CVSS changed · 5.0
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-62376 Vikunja: Plaintext storage of password-reset/email-confirm tokens in database enables account takeover on DB read access 6d
- High CVE-2026-62367 Vikunja: OIDC email-fallback account linking ignores email_verified, enabling local-account takeover 6d
- High CVE-2026-57458 Vikunja: Scoped API token can mint unrestricted OAuth session credentials 6d
- Medium CVE-2026-55064 Vikunja incomplete fix for CVE-2026-35595: Write-only user can detach shared project from parent hierarchy via parent_project_id=0 Aug 28, 2026
- High CVE-2026-55065 Vikunja: Improper Authorization and Authorization Bypass Through User-Controlled Key in code.vikunja.io/api Aug 28, 2026
- High CVE-2026-55066 Vikunja: Cross-tenant IDOR in kanban move-task endpoint via unauthorized body task_id Aug 28, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-55067 is "Vikunja: Authenticated cross-tenant kanban-bucket relocation via `project_view_id` mass-assignment", rated Medium. It affects Vikunja (Go-vikunja); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.0 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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