CVE-2026-87705

HIGH

Published Oct 13, 2026 Modified Oct 16, 2026 CWE-940

Description

Improper verification of source of a communication channel in Windows Hyper-V allows an unauthorized attacker to bypass a security feature over an adjacent network.

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CVSS v3.1 Score

7.4

HIGH

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

EPSS — Exploit Prediction

0.0043

Probability of exploitation

0.38%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-940 CWE-940

References

Other References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-87705

Frequently Asked Questions

What is CVE-2026-87705? +

Improper verification of source of a communication channel in Windows Hyper-V allows an unauthorized attacker to bypass a security feature over an adjacent network. It has a CVSS v3.1 base score of 7.4 (HIGH).

How severe is CVE-2026-87705? +

CVE-2026-87705 has a CVSS v3.1 score of 7.4 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0043, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-87705? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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