CVE-2026-43366
kernel: io_uring/kbuf: check if target buffer list is still legacy on recycle
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 8, 2026
Updated · October 29, 2026
Description
A flaw was found in the Linux kernel. A vulnerability exists in the io_uring/kbuf component related to buffer recycling. There is a time gap where a buffer list, if empty, could be incorrectly upgraded to a ring-provided type. The legacy recycling mechanism fails to properly check the buffer list's existence and type, which could lead to system instability or unexpected behavior.
Statement
Red Hat acknowledges the upstream Linux kernel correction for «io_uring/kbuf» as described in COMMENT_ZERO. Fixes are delivered through standard kernel errata for supported products. Operational exposure depends on whether this subsystem or driver is active in your configuration.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition