Integer underflow in Linux kernel - CVE-2026-31617
Published: April 25, 2026
Vulnerability identifier: #VU127789
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-31617
CWE-ID: CWE-191
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows an attacker with physical access to disclose sensitive information.
The vulnerability exists due to an integer underflow in ncm_unwrap_ntb() in the f_ncm USB gadget component when processing a host-supplied NTB header. An attacker with physical access can provide a crafted NTB header with a too-small block length and out-of-bounds indexes to disclose sensitive information.
The issue can cause adjacent kernel memory to be copied into a network skb.
How to mitigate CVE-2026-31617
Install security update from vendor's repository.