Vikunja Missing Authorization on CalDAV Task Read

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

EPSS

• CVE-2026-35598: 0.22% estimated exploitation activity in the next 30 days; percentile 12.10 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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. Details GetTasksByUIDs at pkg/models/tasks.go:376-393 performs a global database query with no authorization check: The web.Auth parameter is accepted but never used for permission filtering. This function is called by: - GetResource at pkg/routes/caldav/listStorageProvider.go:266 (CalDAV GET) - GetResourcesByList at pkg/routes/caldav/listStorageProvider.go:199 (CalDAV REPORT multiget) All other CalDAV operations enforce authorization: CreateResource checks CanCreate(), UpdateResource checks CanUpdate(), DeleteResource checks CanDelete(). Only the read operations skip authorization. The project ID in the CalDAV URL is ignored. A request to…

Published by the source

10 Apr 2026, 15:34 UTC

Last modified by the source

10 Apr 2026, 19:36 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-48ch-p4gq-x46x

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# Patch Next advisory brief: CVE-2026-35598

Advisory: Vikunja Missing Authorization on CalDAV Task Read
IDs: CVE-2026-35598, GHSA-48ch-p4gq-x46x
Record: https://patchnext.com/advisories/cve-2026-35598 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: code.vikunja.io/api 2.3.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go code.vikunja.io/api: affected <= 2.2.2; fixed in 2.3.0

## Suggested inspection (read-only)
- Go code.vikunja.io/api: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on code.vikunja.io/api.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-48ch-p4gq-x46x (GitHub-reviewed advisory GHSA-48ch-p4gq-x46x lists affected ranges: Go code.vikunja.io/api >=0 <=2.2.2)

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