Cyber Resilience

CVE-2026-33676

Access Control in Vikunja ≤ 2.2.1

Public PoCAccess Control
Published
24 March 2026
Modified
27 March 2026
Patch / advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0033 25th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-33676 is a medium-severity Incorrect Authorization (CWE-863) vulnerability in Vikunja Vikunja. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Information Repositories (T1213); ranked at the 25th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.1, when the Vikunja API returns tasks, it populates the `related_tasks` field with full task objects for all related tasks without checking whether the requesting user has read permission…

more

on those tasks' projects. An authenticated user who can read a task that has cross-project relations will receive full details (title, description, due dates, priority, percent completion, project ID, etc.) of tasks in projects they have no access to. Version 2.2.1 patches the issue.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1213 Data from Information Repositories Collection
Adversaries may leverage information repositories to mine valuable information.
Why these techniques?

Direct unauthorized read access to task objects stored in the Vikunja information repository due to missing cross-project permission checks.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-35596Same product: Vikunja Vikunja
CVE-2026-33313Same product: Vikunja Vikunja
CVE-2026-33312Same product: Vikunja Vikunja
CVE-2026-33668Same product: Vikunja Vikunja
CVE-2026-35598Same product: Vikunja Vikunja
CVE-2026-33316Same product: Vikunja Vikunja
CVE-2026-33678Same product: Vikunja Vikunja
CVE-2026-33334Same product: Vikunja Vikunja
CVE-2026-35601Same product: Vikunja Vikunja
CVE-2026-27116Same product: Vikunja Vikunja

Affected Assets

vikunja
vikunja
≤ 2.2.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-4 Information Flow Enforcement
  • AC-6 Least Privilege
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces authorization checks on every task object returned by the API, preventing disclosure of related_tasks belonging to unauthorized projects.

prevent

Enforces information-flow policy between projects so that task details cannot leak across project boundaries via the related_tasks field.

prevent

Requires that each user account is granted only the minimum project-level permissions needed, reducing the attack surface for cross-project task leakage.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 mostly match
prevents

Defining, enforcing, and reviewing access authorizations and least privilege directly prevents incorrect authorization checks.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Requiring consistency between access rights and classification plus formal approval steps ensures that the authorization logic correctly distinguishes between entities that should and should not be granted access.

prevents

Enforcing policy-driven approval and role-change reviews stops incorrect or stale authorization decisions from remaining in effect after job changes or terminations.

prevents

By tying access rights to identity, device, location and classification, the control reduces the likelihood that an authorization decision will be based on an incorrect or bypassed policy.

References