# CVE-2026-45159: Missing authorization in security-advisories

> A malicious user with a file drop link can upload files to other encrypted folders of the share owner, bypassing intended access restrictions.

- **Severity:** Low 3.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 Jun 2026
- **Updated:** 1 Jun 2026
- **Also known as:** GHSA-p3qw-7gwx-wg24

## What is CVE-2026-45159?

CVE-2026-45159 is a low-severity missing authorization vulnerability in nextcloud security-advisories, published on 1 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Nextcloud is an open source content collaboration platform. From versions 1.15.0 to before 1.15.4, 1.16.0 to before 1.16.3, 1.17.0 to before 1.17.1, and 1.18.0 to before 1.18.1, a malicious user with access to an end-to-end encrypted files drop link was able to also drop files into other end-to-end encrypted folders of the share owner. Reading and modifying of other files was not possible. This issue has been patched in versions 1.15.4, 1.16.3, 1.17.1, 1.18.1, and 2.0.0-rc.7.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-45159?


## How do I fix CVE-2026-45159?

No fix has been published for CVE-2026-45159 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-45159 being exploited?

There is no known exploitation of CVE-2026-45159 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45159 and fix it if it is affected.

What it is: CVE-2026-45159 is a low-severity missing authorization vulnerability in nextcloud security-advisories, published on 1 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-45159 in the wild and no public exploit code.

Affected product: nextcloud security-advisories. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-45159/ (Markdown: https://insights.sbomify.com/CVE-2026-45159/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45159
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45159
- OSV: https://osv.dev/vulnerability/CVE-2026-45159

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45159/
Summaries are generated and may contain mistakes; the official description above is the record.