Vikunja has an IDOR in Task Comments Allows Reading Arbitrary Comments

Exploitation

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

CVSS 4.0

5.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-33313: 0.27% estimated exploitation activity in the next 30 days; percentile 19.78 (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.

An authenticated user can read any task comment by ID, regardless of whether they have access to the task the comment belongs to, by substituting the task ID in the API URL with a task they do have access to. Details The GET /api/v1/tasks/{taskID}/comments/{commentID} endpoint performs an authorization check against the task ID provided in the URL path, then loads the comment by its own ID without verifying it belongs to that task. Root Cause In pkg/models/taskcommentpermissions.go, CanRead constructs a Task using the TaskID from the URL and checks Task.CanRead: In pkg/models/taskcomments.go, getTaskCommentSimple loads the comment by ID only, with NoAutoCondition() explicitly disabling XORM's implicit struct-field filtering: The generic web handler (pkg/web/handler/readone.go) calls CanRead before ReadOne, so the permission check passes against the attacker-controlled task ID, and then ReadOne returns the comment from a completely different task. Attack Scenario 1. Attacker is…

Published by the source

20 Mar 2026, 17:25 UTC

Last modified by the source

25 Mar 2026, 20:53 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-mr3j-p26x-72x4

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# Patch Next advisory brief: CVE-2026-33313

Advisory: Vikunja has an IDOR in Task Comments Allows Reading Arbitrary Comments
IDs: CVE-2026-33313, GHSA-mr3j-p26x-72x4
Record: https://patchnext.com/advisories/cve-2026-33313 (revision 1, source checked 26 Oct 2026, 15:18 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go code.vikunja.io/api: affected <= 2.1.0

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

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## 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-mr3j-p26x-72x4 (GitHub-reviewed advisory GHSA-mr3j-p26x-72x4 lists affected ranges: Go code.vikunja.io/api >=0 <=2.1.0)

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