Out-of-bounds read in Linux kernel - CVE-2026-64403
Published: July 27, 2026
Vulnerability identifier: #VU139573
CSH Severity: Low
CVSS v4: 5.3 [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]
CVE-ID: CVE-2026-64403
CWE-ID: CWE-125
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to out-of-bounds read in l2cap_get_conf_opt() when parsing L2CAP configuration options. A remote attacker can send a specially crafted Bluetooth L2CAP packet to cause a denial of service.
The read occurs before the malformed option is rejected, and up to 4 bytes may be read past the end of the buffer.
Affected software
Linux kernel
How to mitigate CVE-2026-64403
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/687617555cedfb74c9e3cb85d759b908dcb17856
- https://git.kernel.org/stable/c/6b47bdaacfd0045687880177e0987055d8f4765a
- https://git.kernel.org/stable/c/73abbaf91aa33da87c008fb62c148ade561bb606
- https://git.kernel.org/stable/c/7d871e969b941ce25653f7716203a0ea4d07ad4b
- https://git.kernel.org/stable/c/98d93c226bdfaa79bbdd86981921d7f106374225
- https://git.kernel.org/stable/c/996d3da39899aceb8f4910911a3f19a45a7d9d1b
- https://git.kernel.org/stable/c/cca81b4bc672604a84f6d224a55cc77ec7dee619
- https://git.kernel.org/stable/c/f70d4aa88068096f35d73e3a05eff33c0a16b9cd