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TI-2026-86653 Aliases CVE-2026-123511GHSA-fvq6-3pq9-7pfq

Resource exhaustion in Vikunja via CalDAV VTODO RELATED-TO entries

Priority LOW 39CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.

Summary

Vikunja before 2.7.1 contains an uncontrolled resource consumption flaw (CWE-770) in its CalDAV support. An authenticated CalDAV client with low privileges can send VTODOs containing thousands of RELATED-TO properties with repeated unknown UIDs in one PUT request, creating unbounded dummy tasks. The resulting task, relation and event rows bloat the database and overload the event pipeline.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

Description from the CNA

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.

Why it matters now

Fix Fixed vikunja (go-vikunja): 2.7.1

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
go-vikunjavikunjabefore 2.7.12.7.1Patch availableCNA
  • vikunja Vendorgo-vikunja Affected before 2.7.1 Fixed in 2.7.1 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*——go-vikunja
  • cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:* Versions — — ·go-vikunja

Remediation

Update go-vikunja Vikunja to version 2.7.1, which fixes the issue. The sources list no vendor advisory identifier for this fix.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

  • Fix · CNA vikunja (go-vikunja) Fixed in 2.7.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    go-vikunja vikunja 2.7.1

    39 records Highest priority Priority MEDIUM 20 MEDIUM, 19 LOW

    Other records, highest priority first

    • TI-2026-86673 Pagination limit bypass in Vikunja lets users exhaust resourcesPriority MEDIUM 53
    • TI-2026-86654 Vikunja exposes password-reset tokens in access logsPriority MEDIUM 52
    • TI-2026-86670 Insufficient session expiration in Vikunja token middlewarePriority MEDIUM 48
    Show all 39 records →

Timeline

  1. 2026-11-08 Threatist record created from CVE-2026-123511
  2. 2026-11-08 Alias added: GHSA-fvq6-3pq9-7pfq

References

Advisory 1

  • TI-2026-40929 Authorization bypass in go-vikunja Vikunja CVSS 4.0CRITICAL 9.3
  • TI-2026-21967 Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change CVSS 3.1CRITICAL 9.1
  • TI-2026-62115 Vikunja before 2.6.0 Privilege Escalation via Link Share Hash CVSS 4.0HIGH 8.7
  • TI-2026-62108 Vikunja before 2.6.0 Authentication Bypass via CalDAV BasicAuth CVSS 4.0HIGH 8.7
  • TI-2026-62107 Vikunja before 2.6.0 Authentication Bypass via Unthrottled API CVSS 4.0HIGH 8.7
  • TI-2026-26971 Vikunja ahs a TOTP Two-Factor Authentication Bypass via OIDC Login Path CVSS 3.1CRITICAL 9.1
See all 105 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences