CVE-2026-109390 AnyDesk CVE debrief

Who should care

System administrators, security teams, and IT professionals responsible for managing and securing AnyDesk installations should assess exposure and prioritize patching to mitigate potential risks.

Why it matters

CVE-2026-109390 is a critical vulnerability in AnyDesk that allows unauthenticated remote code execution. System administrators and security teams should assess exposure and prioritize patching to mitigate potential risks.

• Potential for remote code execution as root on Linux systems
• Unauthenticated exploitation possible
• High CVSS score indicating critical severity
• Requires verification of exposure and patching to version 8.0.3 or later

Technical summary

The vulnerability is caused by a heap-based buffer overflow in the stream packet handler for mode 5 in the session protocol of AnyDesk before version 8.0.3. This allows unauthenticated remote attackers to execute arbitrary code, as demonstrated on Linux for command execution as root without victim approval for desktop control. The issue arises from a lack of validation for the payload length value. System administrators and security teams should assess exposure and prioritize patching to mitigate potential risks. Affected product deployments should be identified and owners assigned for follow-up.

Defensive priority

High priority for immediate patching or mitigation

Recommended defensive actions

• Immediately patch AnyDesk to version 8.0.3 or later
• Verify and limit exposure of AnyDesk installations
• Monitor for suspicious activity related to AnyDesk
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description, CVSS score, and affected versions. However, the corpus does not establish versions, exploitation, impact, or remediation beyond patching to version 8.0.3 or later.

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.