CVE-2026-53209

Local kernel corruption via oversized announcement prepend

Published Jun 25, 2026 · Updated Jun 25, 2026

An out-of-bounds write in Linux Kernel allows local users to corrupt kernel memory via oversized Bluetooth extended advertising data. The hci_adv_bcast_annoucement() path prepends Broadcast Announcement service data to a full existing payload, then copies the combined data into a temporary buffer without first verifying that it fits. Reachability requires low-privileged local access and a maximum-length extended advertising instance; successful exploitation can expose or alter kernel memory or crash the system.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds write in Linux Kernel allows local users to corrupt kernel memory via oversized Bluetooth extended advertising data. The hci_adv_bcast_annoucement() path prepends Broadcast Announcement service data to a full existing payload, then copies the combined data into a temporary buffer without first verifying that it fits. Reachability requires low-privileged local access and a maximum-length extended advertising instance; successful exploitation can expose or alter kernel memory or crash the system.

The record

CVE
CVE-2026-53209
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=15da883c010cbc2a84aec1738b6ad6ee477846de
  2. Affected versionversion=5725bc608252050ed8a4d47d59225b7dd73474c8 <5c65b96b549ea2dcfde497436bf9e048deb87758
  3. Affected versionversion=5725bc608252050ed8a4d47d59225b7dd73474c8 <cdd8bbdbee763fdf5bf343e6f7d4e79347739f62
  4. Affected versionversion=5725bc608252050ed8a4d47d59225b7dd73474c8 <dafc9f57140e66a10945127aa7433c3d715dc253
  5. Affected versionversion=6.1.142 <6.1.176
  6. Affected versionversion=6.12.34 <6.12.94
  7. Affected versionversion=6.15.3 <6.16
  8. Affected versionversion=6.16
  9. Affected versionversion=63f365eb4d1668a04070151b555d55a07ede8d4b <10b0e832cc05d7aef4b92bed912cbd4a395d0862
  10. Affected versionversion=6.6.94 <6.6.143
  11. Affected versionversion=907ef6e12fb558a0763e894311eb245a94c192dd <02f50e8bb69f9b22516163a09922f5537d3b12d1
  12. Affected versionversion=c621211b308816889f0a3246de448bfcef8ab3ab <1338ee049a8910ba6c9cee963920e978e6893c7d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=15da883c010cbc2a84aec1738b6ad6ee477846de; version=5725bc608252050ed8a4d47d59225b7dd73474c8 <5c65b96b549ea2dcfde497436bf9e048deb87758; version=5725bc608252050ed8a4d47d59225b7dd73474c8 <cdd8bbdbee763fdf5bf343e6f7d4e79347739f62; version=5725bc608252050ed8a4d47d59225b7dd73474c8 <dafc9f57140e66a10945127aa7433c3d715dc253; version=6.1.142 <6.1.176; version=6.12.34 <6.12.94; version=6.15.3 <6.16; version=6.16; version=63f365eb4d1668a04070151b555d55a07ede8d4b <10b0e832cc05d7aef4b92bed912cbd4a395d0862; version=6.6.94 <6.6.143; version=907ef6e12fb558a0763e894311eb245a94c192dd <02f50e8bb69f9b22516163a09922f5537d3b12d1; version=c621211b308816889f0a3246de448bfcef8ab3ab <1338ee049a8910ba6c9cee963920e978e6893c7d

Published CVSS scores

7.8LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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