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CVE-2026-54995 Microsoft CVE debrief

CVE-2026-54995 is a high-severity vulnerability in the Reliable Multicast Transport Driver (RMCAST) that allows an unauthorized attacker to execute code over a network. The vulnerability has a CVSS score of 8.1 and is classified as HIGH. This use-after-free issue can be exploited by sending a specially crafted network request, potentially leading to code execution on affected systems. The vulnerability affects multiple versions of Microsoft Windows 10, Windows 11, and Windows Server. Organizations should prioritize patching to prevent potential code execution attacks.

Vendor
Microsoft
Product
Windows 10 Version 1607
CVSS
HIGH 8.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-14
Original CVE updated
2026-07-20
Advisory published
2026-07-14
Advisory updated
2026-07-20

Who should care

Organizations using Microsoft Windows 10, Windows 11, and Windows Server products should prioritize patching this vulnerability to prevent potential code execution attacks. IT administrators, security teams, and vulnerability management teams should be aware of the vulnerability and take necessary actions to mitigate the risk.

Technical summary

The vulnerability is caused by a use-after-free issue in the Reliable Multicast Transport Driver (RMCAST). An attacker can exploit this vulnerability by sending a specially crafted network request, allowing them to execute code on the affected system. The vulnerability affects multiple versions of Microsoft Windows 10, Windows 11, and Windows Server. Affected organizations should prioritize patching to prevent potential code execution attacks.

Defensive priority

High

Recommended defensive actions

  • Apply the available patch from Microsoft
  • Conduct a thorough inventory of affected systems
  • Implement compensating controls, such as network segmentation and monitoring
  • Verify that the patch has been successfully applied
  • Review relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record was published on 2026-07-14T17:17:07.143Z and last modified on 2026-07-20T17:18:43.320Z. The NVD entry is currently Analyzed. The Reliable Multicast Transport Driver (RMCAST) vulnerability, tracked as CVE-2026-54995, has been publicly disclosed. Evidence of exploitation has not been reported. However, defenders should verify patch application and monitor for suspicious network activity.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-14T17:17:07.143Z and has not been modified since then. The NVD entry is currently Analyzed.