CVE intelligence

CVE-2026-89818

Vulnerability intelligence

Published Sep 16, 2026Sources checked Nov 10, 2026

7.1HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-89818 and is rated High severity with a CVSS score of 7.1. 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: Oct 21, 2026

Release Notes

Vendor-listed releases

6.6.157.1-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.2%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-89818?

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu/vcn: fix integer overflow in dec_msg buffer count check

If the supplied msg[2] (num_buffers) is 0x3FFFFFFF, the expression 6 + num_buffers * 4 wraps to 2 and the bounds check passes, letting the parser loop far past the end of the message BO. Triggering it additionally requires a ~4GiB mapping so that msg[1] survives the earlier "header does not fit in BO" check.

Rewrite the test in division form, which is overflow-free by construction. Also update the message to reflect that msg is invalid.

Source: NVD