CVE-2026-35598 Vikunja has Missing Authorization on CalDAV Task Read
Authenticated users can read task data from any project by guessing task UIDs due to missing authorization checks in CalDAV methods.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-35598?
CVE-2026-35598 is a medium-severity missing authorization vulnerability in go-vikunja vikunja, published on 10 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the CalDAV GetResource and GetResourcesByList methods fetch tasks by UID from the database without verifying that the authenticated user has access to the task's project. Any authenticated CalDAV user who knows (or guesses) a task UID can read the full task data from any project on the instance. This vulnerability is fixed in 2.3.0.
Weakness: CWE-862
Which versions are affected by CVE-2026-35598?
3 open source packages ship an affected version, including code.vikunja.io/api. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
code.vikunja.io/api Go | All versions | None |
code.vikunja.io/api Go | All versions | 2.3.0 |
code.vikunja.io/api Go | All versions | 2.3.0 |
Products include Vikunja Vikunja.
How do I fix CVE-2026-35598?
Upgrade code.vikunja.io/api to 2.3.0 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-35598 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35598 exists.
Other vulnerabilities in go-vikunja vikunja
- CVE-2026-28268 Vikunja Vulnerable to Account Takeover via Password Reset Token Reuse
- CVE-2026-27575 Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change
- CVE-2026-25935 Vikunja Affected by XSS Via Task Preview
- CVE-2026-35595 Vikunja Affected by Privilege Escalation via Project Reparenting
- CVE-2026-33316 Vikunja’s Improper Access Control Enables Bypass of Administrator-Imposed Account Disablement
Sources
Also known as GHSA-48ch-p4gq-x46x, GO-2026-5114.