Vikunja: Write-level project members can delete admin-tier link shares through an unloaded permission check

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2026-111921: 0.21% estimated exploitation activity in the next 30 days; percentile 11.65 (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 A project member with Write permission can delete an admin-tier link share on that project. The deletion authorization check reads the permission from an object populated only with URL IDs, rather than from the stored share. Its zero value is Read, so the check falls through to project Write permission instead of requiring Admin.

Details Affected endpoints: - `DELETE /api/v1/projects/{project}/shares/{share}` - `DELETE /api/v2/projects/{project}/shares/{share}` Older v1 releases used `/lists/{list}/shares/{share}` before lists were renamed to projects. In `pkg/routes/api/v2/link_sharing.go:156`, the delete handler passes `&models.LinkSharing{ID: in.ID, ProjectID: in.ProjectID}` to `handler.DoDelete`. The v1 generic handler likewise binds the URL IDs without loading the stored share. `pkg/web/handler/core.go:185` calls `CanDelete` before `Delete`. `LinkSharing.CanDelete` delegates to `canDoLinkShare` in `pkg/models/link_sharing_permissions.go`. That helper loads the…

Published by the source

9 Oct 2026, 20:57 UTC

Last modified by the source

27 Oct 2026, 15:30 UTC

Source last checked

28 Oct 2026, 06:30 UTC

1. Revision 6 · amended · 28 Oct 2026

   Amended from osv record GHSA-fmmf-xq98-g327

2. Revision 5 · amended · 27 Oct 2026

   Amended from ghsa record GHSA-fmmf-xq98-g327

3. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-fmmf-xq98-g327

4. Revision 3 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

5. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6730

6. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-fmmf-xq98-g327

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# Patch Next advisory brief: CVE-2026-111921

Advisory: Vikunja: Write-level project members can delete admin-tier link shares through an unloaded permission check
IDs: CVE-2026-111921, GHSA-fmmf-xq98-g327
Record: https://patchnext.com/advisories/cve-2026-111921 (revision 6, source checked 28 Oct 2026, 06:30 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
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 2.7.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go code.vikunja.io/api: affected >= 0.13.0, < 2.7.0; fixed in 2.7.0

## 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://osv.dev/vulnerability/GO-2026-6730 (OSV record GO-2026-6730 lists affected ranges: Go code.vikunja.io/api >=0)
- Verified: https://osv.dev/vulnerability/GHSA-fmmf-xq98-g327 (OSV record GHSA-fmmf-xq98-g327 lists affected ranges: Go code.vikunja.io/api >=0.13.0 <=2.6.0)
- Verified: https://github.com/advisories/GHSA-fmmf-xq98-g327 (GitHub-reviewed advisory GHSA-fmmf-xq98-g327 lists affected ranges: Go code.vikunja.io/api >=0.13.0 <=2.6.0)
- Verified: https://osv.dev/vulnerability/GHSA-fmmf-xq98-g327 (OSV record GHSA-fmmf-xq98-g327 lists affected ranges: Go code.vikunja.io/api >=0.13.0 <2.7.0 (fixed))

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