CVE intelligence

CVE-2026-99270

Vulnerability intelligence

Published Nov 3, 2026Sources checked Nov 5, 2026

8.1HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-99270 and is rated High severity with a CVSS score of 8.1. 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 5, 2026

Release Notes

CISA KEVNot listedBased on the latest collected catalog

EPSS0.3%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-99270?

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

tcp: Fix potential UAF in reqsk_timer_handler().

When TCP socket migration fails at inet_ehash_insert() in reqsk_timer_handler(), we jump to the no_ownership: label and free the new reqsk immediately with __reqsk_free().

Thus, we must stop the new reqsk's timer before jumping to the label, but the timer might be missed since the cited commit, resulting in UAF.

As we are in the original reqsk's timer context, we can safely call timer_delete_sync() for the new reqsk.

Let's pass false to __inet_csk_reqsk_queue_drop() to stop the new reqsk's timer.

Source: NVD