Improper input validation in Linux kernel - CVE-2026-53208
Published: June 26, 2026
Vulnerability identifier: #VU135575
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-53208
CWE-ID: CWE-20
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper input validation in l2cap_sig_channel() when processing oversized Bluetooth BR/EDR signaling packets. A remote attacker can send a specially crafted fixed-channel CID 0x0001 packet containing many L2CAP_ECHO_REQ commands to cause a denial of service.
Exploitation is possible by a Bluetooth BR/EDR peer within radio range before pairing.
How to mitigate CVE-2026-53208
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/214a2042b16b3c8d798a8b9ef9f36094f13a9859
- https://git.kernel.org/stable/c/a8335f3db15bd1e0e82e0db5d488fabc7d10d1ab
- https://git.kernel.org/stable/c/b20e8a98dd29b121f58fcdf51e8576119aba536a
- https://git.kernel.org/stable/c/dd214733544427587a95f66dbf3adff072568990
- https://git.kernel.org/stable/c/dedc92b96dc1d8919a3bdf2495ede68922ef7ebc
- https://git.kernel.org/stable/c/e05c4ac575b457978a7ef441053394169084869c
- https://git.kernel.org/stable/c/e2b8acf9405bd9b1baf1c54dc897b0905db689bf
- https://git.kernel.org/stable/c/fa5823126239b3e453fac1a2fe50726c7f4a55e1