CVE-2026-40531 Synology CVE debrief

Who should care

Defenders responsible for Synology DiskStation Manager (DSM) systems should assess exposure and verify DSM versions. Security teams and vulnerability management teams should review the CVE record and Synology's security advisory to understand the vulnerability and apply necessary updates. Operators and administrators of DSM systems should prioritize verification and updates to prevent potential denial-of-service The

Why it matters

CVE-2026-40531 is a medium-severity vulnerability in Synology DiskStation Manager (DSM) that requires verification of DSM versions and updates to prevent potential denial-of-service attacks.

• Denial-of-service attacks may occur if the vulnerability is exploited
• Verification of DSM versions and updates is necessary

Technical summary

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

Defensive priority

Medium

Recommended defensive actions

• Review and apply Synology's security advisory for CVE-2026-40531
• Verify DSM versions and apply updates as necessary
• Monitor for potential denial-of-service attacks

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but the scope of affected versions and remediation steps require verification. Synology's security advisory for CVE-2026-40531 should be reviewed for specific guidance on affected versions and updates. The advisory provides critical information for defenders to assess exposure and apply necessary updates.

Sources and 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.