# CVE-2026-86343: Synology DiskStation Manager SNMP API CRLF injection

Source: https://junglewise.ai/threats/cve-2026-86343-an-improper-neutralization-of-crlf-sequences-vulnerability-in-the  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-12. Updated: 2026-11-12  
License: CC BY 4.0 with a link back

CVE-2026-86343 · Severity: medium · CVSS 6.8 · Published 2026-11-12

Synology DiskStation Manager is a storage management system that runs on network-attached storage devices. An improper handling of line-break sequences in the SNMP service allows an authenticated administrator to read or write arbitrary files and disable the system. This could lead to data theft, data loss, or complete service outage.

Technologies: [Synology DiskStation Manager](https://junglewise.ai/threats/technologies/diskstation-manager). Vendors: [Synology](https://junglewise.ai/threats/vendors/synology).

## Quick answers

**Is CVE-2026-86343 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-86343 being exploited in the wild.

**How severe is CVE-2026-86343?** Medium severity, with a CVSS score of 6.8, published 12 November 2026.

**Which products and versions are affected?** Synology DiskStation Manager 7.3 before 7.3.2-86009-5, 7.4 before 7.4.1-90080-1.

**Is there a fix for CVE-2026-86343?** Yes: fixed in DSM 7.3.2-86009-5, 7.4.1-90080-1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-86343 attacked?** It is attacked from the adjacent network.

**Am I affected by CVE-2026-86343?** Check whether you run Synology DiskStation Manager at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in DSM 7.3.2-86009-5, 7.4.1-90080-1

## Technical details

A CWE-93 CRLF injection vulnerability exists in the SNMP API component of DSM, allowing remote authenticated users with administrator privileges to inject carriage return and line feed sequences. The vulnerability permits arbitrary file read/write operations and denial-of-service attacks. The attack requires network access and valid administrator credentials.

## Affected products

- Synology DiskStation Manager 7.3 before 7.3.2-86009-5, 7.4 before 7.4.1-90080-1

## Timeline

- 2026-11-10: disclosed
- 2026-11-12: advisory

## References

- [https://www.synology.com/en-global/security/advisory/Synology_SA_26_18](https://www.synology.com/en-global/security/advisory/Synology_SA_26_18)

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