CVE-2026-123151 and is rated High severity with a CVSS score of 7.5. 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 11, 2026
Release Notes
CISA KEVNot listedBased on the latest collected catalog
EPSS0.5%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-123151?
A flaw was found in the GNU debugger (GDB). When GDB connects to a remote debug target, a malicious target can cause GDB to overflow a buffer on the stack while parsing the target's replies.
This can crash GDB or potentially allow the target to execute arbitrary code in the GDB client process with the privileges of the user running GDB.