CVE-2026-64557: Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()

highCVSS 7.1CVE-2026-64557

CSIRTS triage

vendor: Linux product: Linux Kernel Memory corruption

What: Use-after-free in Bluetooth L2CAP socket connection callback can lead to memory corruption.
Who is affected: Systems with Bluetooth hardware and L2CAP protocol enabled accepting wireless connections.
Urgency: High priority; use-after-free is readily exploitable and affects core Bluetooth functionality.
Action: Apply kernel patch fixing use-after-free in l2cap_sock_new_connection_cb function.

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

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7.1
Published: 2026-08-06
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64557

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-2026-645570.24% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 15% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-64557	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

unknownMultiple vulnerabilities in Debian LTS Linux kernel (August 07, 2026)cert-fr-avis
unknownMultiple vulnerabilities in Debian Linux kernel (August 07, 2026)cert-fr-avis
medium[NEW] [medium] Linux Kernel: Multiple vulnerabilities allow Denial of Servicecert-bund
highCVE-2026-64557: In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-…nvd

Recent advisories for Bluetooth

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

medium[UPDATE] [medium] Linux Kernel (Bluetooth): Multiple vulnerabilitiescert-bund · 2026-08-06
mediumCVE-2022-50233: Bluetooth: eir: Fix using strlen with hdev->{dev_name,short_name}msrc · 2026-08-06
highCVE-2025-68304: Bluetooth: hci_core: lookup hci_conn on RX path on protocol sidemsrc · 2026-08-06
highCVE-2026-64405: Bluetooth: hci_conn: Fix null ptr deref in hci_abort_conn()msrc · 2026-08-06
mediumCVE-2026-64408: Bluetooth: bnep: pin L2CAP connection during netdev registrationmsrc · 2026-08-06
mediumCVE-2025-38303: Bluetooth: eir: Fix possible crashes on eir_create_adv_datamsrc · 2026-08-06