Out-of-bounds read in Linux kernel - CVE-2026-31774
Published: May 2, 2026
Vulnerability identifier: #VU128924
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-31774
CWE-ID: CWE-125
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 a local user to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in io_bundle_nbufs() when processing oversized sqe->len values through the io_uring bundle recv/send path. A local user can submit crafted io_uring requests to disclose sensitive information.
The issue is triggered by an integer overflow that turns a large __u32 length value into a negative int, which then propagates into an infinite loop that reads past allocated iovec entries.
How to mitigate CVE-2026-31774
Install security update from vendor's repository.