# CVE-2026-111918: Vikunja 1.0.0-rc0 before 2.7.0 Cross-Tenant Task Position Writes via Saved Filter Creation

> Authenticated users can write task positions across all tenants, enabling cross-tenant data modification and denial of service.

- **Severity:** Medium 5.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** GHSA-fprf-r6rv-xg99, GHSA-mjqg-gwhm-xr66, GO-2026-6731

## What is CVE-2026-111918?

CVE-2026-111918 is a medium-severity missing authorization vulnerability in go-vikunja vikunja, published on 17 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Vikunja from 1.0.0-rc0 before 2.7.0 contains an improper authorization vulnerability in RecalculateTaskPositions that allows authenticated users with zero accessible projects to write task_positions rows for all tasks instance-wide. Attackers can delete their Inbox after repointing default_project_id, then create empty-filter saved filters to persist cross-tenant references and amplify writes for denial of service.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-111918?

3 open source packages ship an affected version, including code.vikunja.io/api.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `code.vikunja.io/api` | Go | All versions | None |
| `code.vikunja.io/api` | Go | From 1.0.0-rc0 | 2.7.0 |
| `code.vikunja.io/api` | Go | From 1.0.0-rc0 | 2.7.0 |

## How do I fix CVE-2026-111918?

Upgrade code.vikunja.io/api to 2.7.0 or later.

## Is CVE-2026-111918 being exploited?

There is no known exploitation of CVE-2026-111918 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111918 and fix it if it is affected.

What it is: CVE-2026-111918 is a medium-severity missing authorization vulnerability in go-vikunja vikunja, published on 17 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-111918 in the wild and no public exploit code.

Affected packages and fixed versions:
- code.vikunja.io/api (Go): affected all versions; no fix listed
- code.vikunja.io/api (Go): affected from 1.0.0-rc0; fixed in 2.7.0
- code.vikunja.io/api (Go): affected from 1.0.0-rc0; fixed in 2.7.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-111918/ (Markdown: https://insights.sbomify.com/CVE-2026-111918/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111918
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111918
- OSV: https://osv.dev/vulnerability/CVE-2026-111918

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-111918/
Summaries are generated and may contain mistakes; the official description above is the record.