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CVE-2026-49788 Microsoft CVE debrief

CVE-2026-49788 is a HIGH severity vulnerability with a CVSS score of 7.5, involving allocation of resources without limits or throttling in HTTP/2. This allows an unauthorized attacker to deny service over a network. The vulnerability exists in the HTTP/2 protocol implementation, enabling an attacker to cause a denial of service (DoS) by exhausting system resources. Microsoft has released patches for affected products. System administrators and security teams should be aware of this vulnerability, particularly those managing and securing network infrastructure using Microsoft products and services. The CVE record was published on 2026-07-14T17:16:54.207Z and last modified on 2026-07-20T12:44:43.300Z.

Vendor
Microsoft
Product
Windows 10 Version 1607
CVSS
HIGH 7.5
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

System administrators and security teams responsible for managing and securing network infrastructure, particularly those using Microsoft products and services, should be aware of this vulnerability. These teams should review their current configurations, assess potential exposure, and plan for the implementation of patches or mitigations as necessary. Additionally, security teams should monitor network traffic for unusual patterns indicative of potential attacks and review incident response plans to address potential DoS attacks.

Technical summary

The vulnerability exists in the HTTP/2 protocol implementation, allowing an attacker to cause a denial of service (DoS) by exhausting system resources. Microsoft has released patches for affected products. The vulnerability is caused by the allocation of resources without limits or throttling in HTTP/2. This can lead to a denial of service (DoS) attack, which can have significant operational impacts on network infrastructure. Further review of system configurations and implementation of compensating controls may be necessary.

Defensive priority

High priority should be given to patching affected systems, especially those exposed to the internet or critical network infrastructure. Implementing network segmentation and isolation for critical infrastructure, monitoring network traffic for unusual patterns indicative of potential attacks, and reviewing incident response plans to address potential DoS attacks are also recommended.

Recommended defensive actions

  • Apply patches provided by Microsoft for affected products
  • Implement network segmentation and isolation for critical infrastructure
  • Monitor network traffic for unusual patterns indicative of potential attacks
  • Consider implementing rate limiting or traffic shaping for HTTP/2 traffic
  • Review and update incident response plans to address potential DoS attacks

Evidence notes

The CVE record was published on 2026-07-14T17:16:54.207Z and last modified on 2026-07-20T12:44:43.300Z. The NVD entry is currently Analyzed. This vulnerability affects HTTP/2 protocol implementation, allowing an attacker to cause a denial of service (DoS) by exhausting system resources. Microsoft has released patches for affected products. However, details on the specific products affected and the extent of the vulnerability are limited in the provided source corpus. Further verification is recommended to understand the full scope of this vulnerability.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-14T17:16:54.207Z and has not been modified since then. The NVD entry is currently Analyzed.