CVE-2026-64434: Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref

CSIRTS triage

What

The vulnerability is a use-after-free (UAF) issue in the Bluetooth L2CAP channel timeout handling.

Who is affected

Users of Bluetooth L2CAP are affected by this vulnerability.

Urgency

Immediate remediation is advised due to the potential for exploitation leading to UAF issues.

Action

Implement the fix for the UAF in Bluetooth L2CAP channel timeout.

AI-assisted analysis generated from the source advisory — verify against the original.

Details

Source

Microsoft Security Response Center (INTL · vendor-psirt · site)

Severity

medium — CVSS 6.3

Published

2026-07-14

Exploitation

Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64434

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

• Low exploitation riskCVE-2026-644340.25% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 16% of all scored CVEs.

Referenced CVEs

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

• unknownDSA-6405-1 linux - security updatedebian
• highCVE-2026-64434: In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix UAF …nvd

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