Out-of-bounds write in Linux kernel - CVE-2026-63962
Published: July 20, 2026
Vulnerability identifier: #VU138682
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-63962
CWE-ID: CWE-787
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 overwrite adjacent memory.
The vulnerability exists due to an out-of-bounds write in svdm_consume_modes() when processing an unsolicited Discover Modes ACK containing crafted VDOs from a connected port partner. A remote attacker can send a crafted Discover Modes ACK to overwrite adjacent memory.
Exploitation is possible after the port partner is set because incoming Discover Modes ACK messages are consumed without being correlated to a request sent by the port.
How to mitigate CVE-2026-63962
Install security update from vendor's repository.