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TI-2026-27702 Aliases CVE-2026-35599GHSA-r4fg-73rc-hhh7

Vikunja has an Algorithmic Complexity DoS in Repeating Task Handler

Priority MEDIUM 62CWE-407Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-407.

Summary

Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the addRepeatIntervalToTime function uses an O(n) loop that advances a date by the task's RepeatAfter duration until it exceeds the current time. By creating a repeating task with a 1-second interval and a due date far in the past, an attacker triggers billions of loop iterations, consuming CPU and holding a database connection for minutes per request. This vulnerability is fixed in 2.3.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00361 30th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed vikunja (go-vikunja): 2.3.0code.vikunja.io/api (Go): 2.3.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
go-vikunjavikunjabefore 2.3.02.3.0Patch availableCNA
—code.vikunja.io/api (Go)before 2.3.02.3.0Patch availableGHSA-r4fg-73rc-hhh7
  • vikunja Vendorgo-vikunja Affected before 2.3.0 Fixed in 2.3.0 Patch available CNA
  • code.vikunja.io/api (Go) Vendor— Affected before 2.3.0 Fixed in 2.3.0 Patch available GHSA-r4fg-73rc-hhh7

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*before 2.3.0Vulnerablego-vikunja
  • cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:* Versions before 2.3.0 Vulnerable ·go-vikunja

Remediation

  • Fix · CNA vikunja (go-vikunja) Fixed in 2.3.0
  • Fix · GHSA-r4fg-73rc-hhh7 code.vikunja.io/api (Go) Fixed in 2.3.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-35599
  2. 2026-10-03 Alias added: GHSA-r4fg-73rc-hhh7

References

Exploit 1

Patch 1

Advisory 1

Other 3

  • TI-2026-21967 Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change CVSS 3.1CRITICAL 9.1
  • TI-2026-26971 Vikunja ahs a TOTP Two-Factor Authentication Bypass via OIDC Login Path CVSS 3.1CRITICAL 9.1
  • TI-2026-26060 Vikunja Vulnerable to Link Share Hash Disclosure via ReadAll Endpoint Enables Permission Escalation CVSS 3.1HIGH 7.5
  • TI-2026-20965 Vikunja Affected by XSS Via Task Preview CVSS 4.0HIGH 8.6
  • TI-2026-27698 Vikunja Affected by Privilege Escalation via Project Reparenting CVSS 3.1HIGH 8.3
  • TI-2026-25727 Vikunja’s Improper Access Control Enables Bypass of Administrator-Imposed Account Disablement CVSS 3.1HIGH 8.1
See all 34 →

Sources

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