# CVE-2026-55168: Runtipi: Authenticated arbitrary file write via backup restore symlink planting

> An authenticated attacker can exploit symlink handling in backup restore to write arbitrary files, potentially leading to code execution or privilege escalation.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** GHSA-wcrf-g9p9-2wg7

## What is CVE-2026-55168?

CVE-2026-55168 is a medium-severity path traversal vulnerability in runtipi, published on 21 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Runtipi is a personal homeserver orchestrator. In 4.10.0 and earlier, Runtipi accepts symbolic links from an attacker-controlled backup archive and copies them into live application paths during the backup restore flow. An authenticated attacker can plant user-config/app.env as a symlink to an arbitrary reachable path and then send PUT /api/user-config/demoapp3:_user with attacker-controlled appEnv content. FilesystemService.writeTextFile() follows the planted link, allowing content to be written outside the intended restore and user-config directory boundary with Runtipi process permissions. This issue is fixed in version 4.10.1.

Weakness: CWE-61 (UNIX Symbolic Link (Symlink) Following), CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2026-55168?


## How do I fix CVE-2026-55168?

No fix has been published for CVE-2026-55168 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-55168 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55168 exists.

Public exploit code:

- https://github.com/KovachVL/CVE-2026-55168 (github_poc): https://github.com/KovachVL/CVE-2026-55168

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55168 and fix it if it is affected.

What it is: CVE-2026-55168 is a medium-severity path traversal vulnerability in runtipi, published on 21 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55168 exists.

Affected product: runtipi. 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-2026-55168/ (Markdown: https://insights.sbomify.com/CVE-2026-55168/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55168
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55168
- OSV: https://osv.dev/vulnerability/CVE-2026-55168

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55168/
Summaries are generated and may contain mistakes; the official description above is the record.