What’s Vulnerable › Vulnerabilities

CVE-2026-35599: Vikunja has an Algorithmic Complexity DoS in Repeating Task Handler

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-04-10 · updated 2026-10-26
• Weakness: CWE-407

Description

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.

Affected products

• go-vikunja vikunja: before 2.3.0 — fixed in 2.3.0

How to fix

Upgrade to a fixed version: go-vikunja vikunja 2.3.0. Check the vendor advisory for mitigations.

References

• https://github.com/go-vikunja/vikunja/commit/6df0d6c8f54b01db6464c42810e40e55f12b481b
• https://github.com/go-vikunja/vikunja/pull/2577
• https://github.com/go-vikunja/vikunja/releases/tag/v2.3.0
• https://github.com/go-vikunja/vikunja/security/advisories/GHSA-r4fg-73rc-hhh7

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