What is CVE-2026-53209?

CVE-2026-53209 is a high-severity vulnerability in Linux, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2026-06-25.

How severe is CVE-2026-53209?

High severity. CVSS v3 base score is 7.8 out of 10.

Buffer overflow in Linux

CVE-2026-53209

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: reject oversized Broadcast Announcement prepend Existing advertising instances can already hold the maximum extended advertising payload. When hci_a…

Vulnerability class: Buffer Overflow

EPSS: 0.001 (3.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Linux — versions 63f365eb4d1668a04070151b555d55a07ede8d4b, c621211b308816889f0a3246de448bfcef8ab3ab, 907ef6e12fb558a0763e894311eb245a94c192dd
Linux Linux_kernel — versions 6.16, 7.1

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)

Frequently asked questions

What is CVE-2026-53209?: CVE-2026-53209 is a high-severity vulnerability in Linux, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2026-06-25.
How severe is CVE-2026-53209?: High severity. CVSS v3 base score is 7.8 out of 10.