Linux Linux Kernel Vulnerability Rated 7.8 CVSS

Last refreshed2026-10-15

Status: UPDATED | Advisory ID: CVE-2026-74544

Key Details

CVE	CVE-2026-74544
CVSS Score / Version	7.8 (High) / CVSS v3.1
Updated	2026-10-15
CVSS Vector	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`
CVSS Prose	attack vector is local; attack complexity is low; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high.
Affected products	Linux Kernel
Exploitation prediction (EPSS)	0.17% probability of exploitation in the next 30 days (5% percentile) -- FIRST.org's EPSS model.

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/sched: cls_u32: validate offshift to prevent shift-out-of-bounds

u32_change() copies the user-provided tc_u32_sel.offshift (unsigned char,

0-255) into the kernel knode object without bounds validation. When a

packet later hits u32_classify() with TC_U32_VAROFFSET set, it evaluates

`ntohs(offmask & *data) >> offshift` where the left operand is a 16-bit

value promoted to a 32-bit int. Any offshift >= 32 is undefined behavior

per C11 6.5.7p3, triggerable by an unprivileged user via user/network

namespaces.

UBSAN: shift-out-of-bounds in net/sched/cls_u32.c:236:43

shift exponent 32 is too large for 32-bit type int

Fix this by rejecting offshift >= 16 during filter creation in

u32_change(). (NVD)

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

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-74544
CVE	https://www.cve.org/CVERecord?id=CVE-2026-74544

Source

Reference

NVD

CVE