Description
Vikunja before 2.7.1 contains an uncontrolled resource consumption vulnerability that allows authenticated CalDAV clients to create unbounded dummy tasks by sending VTODOs with thousands of RELATED-TO properties. Attackers can repeat unknown related UIDs in a single PUT request to generate thousands of task, relation, and event rows, bloating the database and overloading the event pipeline.
Published: 2026-11-08
Score: 5.3 Medium
EPSS: n/a
KEV: No
Impact: Resource Exhaustion
Action: Patch
AI Analysis

Impact

Vikunja before version 2.7.1 allows an authenticated CalDAV client to send a VTODO containing thousands of RELATED-TO properties. Each property causes the server to create a dummy task, relation, or event row, which can rapidly inflate the database size and saturate the event processing pipeline. This uncontrolled resource consumption can lead to denial of service conditions for the application and its underlying infrastructure.

Affected Systems

The affected product is Vikunja, with all releases prior to 2.7.1 susceptible to this vulnerability. No precise sub‑versions are listed, so any instance of Vikunja older than 2.7.1 is at risk.

Risk and Exploitability

The problem is rated with a CVSS score of 5.3, indicating a moderate severity scenario. The EPSS score is not available, but the vulnerability is not currently in the CISA KEV catalog. Attackers must be authenticated to a CalDAV endpoint and can exploit the flaw by crafting a single PUT request containing many repeated UIDs in the RELATED-TO properties. Each request can create thousands of rows, exhausting database storage and processing resources. The attack vector is strictly authenticated via CalDAV, and the impact is a denial of service due to resource exhaustion.

Generated by OpenCVE AI on November 8, 2026 at 02:26 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade Vikunja to version 2.7.1 or later, which contains the necessary fixes for the resource exhaustion issue.
  • Restrict CalDAV usage to trusted users only and enforce limits on VTODO creation, such as capping the number of RELATED-TO properties per request.
  • Implement monitoring on database size and event queue usage to detect sudden growth patterns and trigger alerts for potential abuse.

Generated by OpenCVE AI on November 8, 2026 at 02:26 UTC.

Tracking

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Advisories

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History

Sun, 08 Nov 2026 01:45:00 +0000

Type Values Removed Values Added
Description Vikunja before 2.7.1 contains an uncontrolled resource consumption vulnerability that allows authenticated CalDAV clients to create unbounded dummy tasks by sending VTODOs with thousands of RELATED-TO properties. Attackers can repeat unknown related UIDs in a single PUT request to generate thousands of task, relation, and event rows, bloating the database and overloading the event pipeline.
Title Vikunja before 2.7.1 Resource Exhaustion via CalDAV VTODO RELATED-TO Entries
First Time appeared Vikunja
Vikunja vikunja
Weaknesses CWE-770
CPEs cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*
Vendors & Products Vikunja
Vikunja vikunja
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}

Subscriptions

Vikunja Vikunja
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-08T01:37:24.519Z

Reserved: 2026-11-06T00:46:28.480Z

Link: CVE-2026-123511

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-08T02:16:39.670

Modified: 2026-11-08T02:16:39.797

Link: CVE-2026-123511

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-08T02:30:15Z

Weaknesses
  • CWE-770

    Allocation of Resources Without Limits or Throttling