8.0High

CVE-2026-40530

An improper neutralization of CRLF sequences ('CRLF injection') vulnerability in User API in Synology DiskStation Manager (DSM) before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2 allows remote authenticated users to read or write arbitrary files and conduct denial-of-service attacks after the system is rebooted.

What this means for your business

  • An attacker can use it remotely, over a network, with an ordinary user login, but only after tricking someone into an action such as opening a file or a link.
  • FIRST's prediction model gives it a 0.3% chance of attack attempts being seen in the next 30 days, ranking above 28% of all known flaws.

What to do

  1. 1Ask your IT team or provider whether any of your systems use the affected product.
  2. 2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
8.0 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Weakness
CWE-93
Assigned by
security@synology.com

Dates

Published
2026-09-18
Last modified
2026-09-18
Sources
NVD

References