CVE-2026-64034

Last refreshed2026-10-13

Status: UPDATED | Advisory ID: CVE-2026-64034

Key Details

CVE	CVE-2026-64034
CVSS Score / Version	9.3 (Critical) / CVSS v3.1
Updated	2026-10-13
CVSS Vector	`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`
CVSS Prose	attack vector is local; attack complexity is low; privileges required is none; user interaction is none; scope is changed; confidentiality impact is high; integrity impact is high; availability impact is high.
Affected products	Linux Kernel
Classified as	CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

Vendor	Product	Affected Versions	Patch Status
Linux	Linux Kernel

Vendor

Product

Affected Versions

Patch Status

Linux

Linux Kernel

Subsystems	OT Supporting Infrastructure
Sectors	All Sectors

In the Linux kernel, the following vulnerability has been resolved:

net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer

In mana_hwc_rx_event_handler(), resp->response.hwc_msg_id is read from

DMA-coherent memory and bounds-checked, then mana_hwc_handle_resp()

re-reads the same field from the same DMA buffer for test_bit() and

pointer arithmetic.

DMA-coherent memory is mapped uncacheable on x86 and is shared,

unencrypted, in Confidential VMs (SEV-SNP/TDX), so each load goes

directly to host-visible memory. A H/W can modify the value

between the check and the use, bypassing the bounds validation.

Fix this by reading hwc_msg_id exactly once using READ_ONCE() into a

stack-local variable in mana_hwc_rx_event_handler(), and passing the

validated value as a parameter to mana_hwc_handle_resp(). (NVD)

Monitor Linux's web page for any future patch releases.

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-64034
CVE	https://www.cve.org/CVERecord?id=CVE-2026-64034

Source

Reference

NVD

CVE