CVE-2026-55401: Microsoft Secure Access vulnerability

Published Aug 13, 2026
·
Updated

CVE-2026-55401 is a null dereference vulnerability on the load-balancing sub-system of Secure Access servers prior to 14.57. Attackers can send an unauthenticated packet to a Secure Access server with load balancing enabled, which results in the internal load balancer crashing. After a successful attack, the Secure Access server is still able to accept connections and is still able to issue a failover to connected clients. ‍ https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L

Affected Software

1 affected component
Microsoft Secure Access<14.57

Event History

Aug 13, 2026
CVE Published
via MITRE·04:11 PM
Data Sourced
via MITRE·04:11 PM
Description
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Frequently Asked Questions

1

What is the severity of CVE-2026-55401?

The severity rating of CVE-2026-55401 is 25.

2

How do I fix CVE-2026-55401?

To fix CVE-2026-55401, update your Microsoft Secure Access servers to version 14.57 or later.

3

What systems are affected by CVE-2026-55401?

CVE-2026-55401 affects Microsoft Secure Access servers prior to version 14.57.

4

What type of vulnerability is CVE-2026-55401?

CVE-2026-55401 is classified as a null dereference vulnerability.

5

What is the impact of CVE-2026-55401?

Exploitation of CVE-2026-55401 can cause the internal load balancer to crash, disrupting service.

Contact

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