# CVE-2026-111920: Vikunja 2.6.0 Broken Access Control via Inherited Project Permissions

> A collaborator with write access to a parent project can improperly modify tasks in child projects due to flawed permission inheritance logic.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/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:** 18 Oct 2026
- **Also known as:** GHSA-pjr3-86v4-5p7w, GHSA-r72j-vqhw-6264, GO-2026-6745

## What is CVE-2026-111920?

CVE-2026-111920 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 2.6.0 contains a broken access control flaw in getProjectAccessForUser (pkg/models/project_access.go), which resolves a user's effective project permission as the maximum over the project tree, silently overriding explicit lower-permission shares on sub-projects. A collaborator with write access on a parent project but read-only access to a child project can modify the child project's tasks and content.

Weakness: CWE-269 (Improper Privilege Management)

## Which versions are affected by CVE-2026-111920?

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 2.6.0 | 2.7.0 |
| `code.vikunja.io/api` | Go | From 2.6.0 | 2.7.0 |

## How do I fix CVE-2026-111920?

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

## Is CVE-2026-111920 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-111920 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111920 and fix it if it is affected.

What it is: CVE-2026-111920 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-111920 exists.

Affected packages and fixed versions:
- code.vikunja.io/api (Go): affected all versions; no fix listed
- code.vikunja.io/api (Go): affected from 2.6.0; fixed in 2.7.0
- code.vikunja.io/api (Go): affected from 2.6.0; 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-2026-111920/ (Markdown: https://insights.sbomify.com/CVE-2026-111920/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111920
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111920
- OSV: https://osv.dev/vulnerability/CVE-2026-111920

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-111920/
Summaries are generated and may contain mistakes; the official description above is the record.