---
id: "CVE-2026-88266"
page: "https://infrastack.ai/live/CVE-2026-88266"
kind: "vulnerability"
aliases: ["CVE-2026-88266"]
title: "Synology DSM: authenticated users can write files via synomount"
severity: "medium"
cvss: 4.3
epss: null
exploited: false
status: "open"
category: "vendor"
products: []
ecosystems: []
tags: ["dsm", "nas", "self-hosted", "synology", "vendor"]
not_affected_if: ["dsm-patched", "no-user-accounts-exposed"]
published_at: "2026-11-12T04:17:22+00:00"
first_seen_at: "2026-11-12T04:47:10+00:00"
updated_at: "2026-11-12T04:48:01+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-88266", "first_seen_at": "2026-11-12T04:47:10+00:00"}]
exploit_sources: []
---

# Synology DSM: authenticated users can write files via synomount

Link for people: https://infrastack.ai/live/CVE-2026-88266 (this .md is for agents)

A flaw in synomount, a component of Synology DiskStation Manager (DSM), lets a logged-in remote user write specific files on the NAS. The sources describe this as an external control of system or configuration setting weakness with a CVSS score of 4.3.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Open DSM and check the installed version under Control Panel > Info Center (unknown path if the sources do not say more)
- Compare the installed version with the fixed versions listed below

## Fix

- DSM before `7.3.2-86009-5` is affected; move to `7.3.2-86009-5` or later
- DSM before `7.4.1-90080-1` is affected; move to `7.4.1-90080-1` or later

## Timeline

- 2026-11-12T04:47:10+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-88266

## From the sources

An external control of system or configuration setting vulnerability in the synomount in Synology DiskStation Manager (DSM) before 7.3.2-86009-5 and 7.4.1-90080-1 allows remote authenticated users to write specific files.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_