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

Advisory record · `GHSA-fmmf-xq98-g327`

- **Identifiers:** `GHSA-fmmf-xq98-g327` · `CVE-2026-111921` · `GO-2026-6730`
- **State:** Confirmed
- **Severity:** CVSS 5.3 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-863](https://cwe.mitre.org/data/definitions/863.html)
- **Tags:** [Broken access control](https://agentprime.io/advisories/tag/access-control.md)
- **Published:** 9 Oct 2026
- **Updated:** 27 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 9 Oct 2026, 20:57 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `code.vikunja.io/api` (Go): affected `>=0.13.0, <2.7.0`; fixed in `2.7.0`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Vikunja (code.vikunja.io/api) versions 0.13.0 up to 2.7.0 are affected. A project member with Write permission can delete an admin-tier link share on that project, which revokes external access through that link, provided they know or guess the numeric share ID. Upgrade to Vikunja 2.7.0 or later.

Written 1 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 5.3 Medium, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N`, from CNA (VulnCheck)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0021, the 11th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:11 UTC: First seen by agentprime
- 31 Oct 2026, 14:11 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-fmmf-xq98-g327)

## Sources

- [GitHub Advisory Database: GHSA-fmmf-xq98-g327](https://github.com/advisories/GHSA-fmmf-xq98-g327)
- [OSV: GHSA-fmmf-xq98-g327](https://osv.dev/vulnerability/GHSA-fmmf-xq98-g327)
- <https://github.com/go-vikunja/vikunja/security/advisories/GHSA-fmmf-xq98-g327>
- <https://github.com/go-vikunja/vikunja/commit/60e543777b4d3ec8376f5485911cdec697e8c8ee>
- <https://github.com/go-vikunja/vikunja>
- <https://github.com/go-vikunja/vikunja/releases/tag/v2.7.0>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-fmmf-xq98-g327>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-fmmf-xq98-g327/>. Everything for agents: <https://agentprime.io/llms.txt>.