# CVE-2026-45279: Nextcloud: Limited path traversal via template API if using `{lang}` in config

> Non-admin users can copy arbitrary files into their directory via path traversal if the template config uses {lang}, requiring an upgrade.

- **Severity:** Medium 4.4 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Jun 2026
- **Updated:** 2 Jun 2026
- **Also known as:** GHSA-j33j-qph5-4wch

## What is CVE-2026-45279?

CVE-2026-45279 is a medium-severity path traversal vulnerability in Nextcloud Nextcloud Server, published on 1 Jun 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 31.0.0 to before 31.0.14, and 32.0.0 to before 32.0.4, if {lang} is used in the template directory config value, non-admin users can in some cases copy arbitrary files (depending on unix permissions) into their own Nextcloud directory via a path traversal. It is recommended that the Nextcloud Server is upgraded to 32.0.4, 31.0.14. It is recommended that the Nextcloud Enterprise Server is upgraded to 32.0.4, 31.0.14, 30.0.17.7, 29.0.17.12, 28.0.14.15

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-45279?

It affects 1 product.


Products: Nextcloud Nextcloud Server.

## How do I fix CVE-2026-45279?

No fix has been published for CVE-2026-45279 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-45279 being exploited?

There is no known exploitation of CVE-2026-45279 in the wild and no public exploit code.

## Other vulnerabilities in Nextcloud Nextcloud Server

- [CVE-2021-32802](https://insights.sbomify.com/CVE-2021-32802/): Preview generation used third-party library not suited for user-generated content in Nextcloud server (critical 9.3)
- [CVE-2023-26482](https://insights.sbomify.com/CVE-2023-26482/): Scope of workflow operations is not validated in nextcloud server (critical 9.1)
- [CVE-2018-3775](https://insights.sbomify.com/CVE-2018-3775/): Auth bypass in Nextcloud Server (high 8.8)
- [CVE-2023-35172](https://insights.sbomify.com/CVE-2023-35172/): Nextcloud Server password reset endpoint is not brute force protected (high 8.7)
- [CVE-2023-32320](https://insights.sbomify.com/CVE-2023-32320/): Nextcloud Server's brute force protection allows someone to send more requests than intended (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45279 and fix it if it is affected.

What it is: CVE-2026-45279 is a medium-severity path traversal vulnerability in Nextcloud Nextcloud Server, published on 1 Jun 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45279 in the wild and no public exploit code.

Affected product: Nextcloud Nextcloud Server. 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-2026-45279/ (Markdown: https://insights.sbomify.com/CVE-2026-45279/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45279
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45279
- OSV: https://osv.dev/vulnerability/CVE-2026-45279

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45279/
Summaries are generated and may contain mistakes; the official description above is the record.