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PatchSiren cyber security CVE debrief

CVE-2026-40531 Synology CVE debrief

CVE-2026-40531 is an integer overflow or wraparound vulnerability in Synology DiskStation Manager (DSM). The vulnerability allows remote authenticated users to conduct limited denial-of-service (DoS) attacks. Affected versions include DSM before 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2. System administrators and security teams should assess exposure and apply patches or mitigations as needed. The CVE record and NVD entry provide details on the vulnerability. Synology has published an advisory (Synology_SA_26_06).

Vendor
Synology
Product
DiskStation Manager (DSM)
CVSS
MEDIUM 4.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-18
Original CVE updated
2026-09-18
Advisory published
2026-09-18
Advisory updated
2026-09-18

Who should care

System administrators and security teams responsible for Synology DiskStation Manager (DSM) systems should assess exposure and apply patches or mitigations as needed.

Why it matters

CVE-2026-40531 is a medium-severity vulnerability in Synology DiskStation Manager (DSM) that allows remote authenticated users to conduct limited denial-of-service (DoS) attacks. System administrators and security teams should verify exposure, apply patches or mitigations, and monitor system activity.

  • Potential limited denial-of-service (DoS) attacks against DSM systems.
  • Verification of patch deployment priority for exposed systems.
  • Monitoring of DSM system activity for unusual patterns.

Technical summary

CVE-2026-40531 is an integer overflow or wraparound vulnerability in File Operation in Synology DiskStation Manager (DSM). The vulnerability allows remote authenticated users to conduct limited denial-of-service (DoS) attacks. Affected versions include DSM before 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2.

Defensive priority

Medium-priority verification and patching recommended.

Recommended defensive actions

  • Verify and apply patches from Synology for DiskStation Manager (DSM) versions before 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2.
  • Restrict access to File Operation features in DSM to trusted users.
  • Monitor DSM systems for unusual activity indicative of potential DoS attempts.

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. Synology has published an advisory (Synology_SA_26_06). The vulnerability allows remote authenticated users to conduct limited denial-of-service (DoS) attacks. Affected versions include DSM before 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2. The source confidence is limited, and defenders should verify the exposure of their systems. The CVE record was published on 2026-09-18T09:16:40.357Z and has not been modified.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-40531 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-40531

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-40531 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-40531

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.