---
title: "CVE-2026-13639: Synology DiskStation Manager (DSM) vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-13639/
description: "CVE-2026-13639 (Synology DiskStation Manager (DSM)): An insufficient entropy vulnerability in login logic in Synology DiskStation Manager (DSM) before…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-09-18
date_modified: 2026-11-03
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-13639"
kev: false
cvss: 9.8
epss: 0.00665
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-13639: Synology DiskStation Manager (DSM) vulnerability

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.7% , percentile 52: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 52% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Editorial verdict: Act now. Synology DSM: C3RB3R Ransomware Hits Unpatched NAS — Ransomware operators are encrypting Synology NAS boxes through DSM flaws that were patched in September 2026 and late 2024; if your DSM is behind the SA-26:13 builds, update today and get its admin interface off the internet.

## What it is

An insufficient entropy vulnerability in login logic in Synology DiskStation Manager (DSM) before 7.2.1-69057-12, 7.2.2-72806-9, 7.3.2-86009-4 and 7.4-90075 allows remote attackers to read or write arbitrary files and conduct denial-of-service attacks.

## Affected products (CVE record)

- Synology DiskStation Manager (DSM): 7.4 < 7.4-90075, 7.3.2 < 7.3.2-86009-4, 7.2.2 < 7.2.2-72806-9, 7.2.1 < 7.2.1-69057-12

## Severity

- synology CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-11-05): 0.66% probability of exploitation activity in the next 30 days; percentile 52.

## Sources

- [CVE.org record CVE-2026-13639](https://www.cve.org/CVERecord?id=CVE-2026-13639)
- [NVD entry CVE-2026-13639](https://nvd.nist.gov/vuln/detail/CVE-2026-13639)
- [Synology-SA-26:13 DSM](https://www.synology.com/en-global/security/advisory/Synology_SA_26_13)

---
Source page: https://erroneo.us/security/cve/CVE-2026-13639/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt