CVE Database›Document archive›CVE-2026-43366

CVE-2026-43366

kernel: io_uring/kbuf: check if target buffer list is still legacy on recycle

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Severity

Moderate

Red Hat Product Security

5.5

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 · 5.5
CVSS: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