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Vulnerability · Published Aug 21, 2026 · Assigned by GitHub_M

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

Medium 6.5

In plain English

A medium-severity security flaw in runtipi from runtipi. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.6%top 50.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack tooling1Public PoC

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.

Affected products (as reported)

VendorProductVersions
runtipi runtipi < 4.10.1

Weakness: CWE-59, CWE-61 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H

References