CVE intelligence

CVE-2026-39830

Vulnerability intelligence

Published May 22, 2026Sources checked Nov 11, 2026

9.1CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-39830 and is rated Critical severity with a CVSS score of 9.1. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Nov 4, 2026

Vendor remediation details

CBL-Mariner Releases

Vendor-listed releases

1.12.15-8
8.7.11-6
0.14.0-13
2.27.0-11
2.62.0-16
1.30.10-25
1.7.1-5
25.0.3-18
1.17.8-3
1.9.5-14
1.31.0-21

CISA KEVNot listedBased on the latest collected catalog

EPSS0.7%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-39830?

A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection.

Unsolicited global responses are now discarded.

Source: NVD