CVE-2026-53209: Bluetooth: hci_sync: reject oversized Broadcast Announcement prepend

highCVSS 7CVE-2026-53209

CSIRTS triage

Other

What: This vulnerability involves rejecting oversized Broadcast Announcement prepend in Bluetooth.
Who is affected: Deployments using Bluetooth technology.
Urgency: Remediation is urgent due to the high severity rating.
Action: Apply the latest patches to mitigate this issue.

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

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7
Published: 2026-06-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53209

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-2026-532090.18% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 7% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-53209	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 Microsoft Azure Linux (June 29, 2026)cert-fr-avis

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.

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medium[UPDATE] [medium] Linux Kernel (Bluetooth): Multiple vulnerabilities allow Denial of Servicecert-bund · 2026-08-25
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