What is CVE-2026-74544?

CVE-2026-74544 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 2.6.12 onward and patched in 7.1.8 and 7.2. CVE-2026-74544 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-74544?

CVE-2026-74544 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-74544?

Yes, CVE-2026-74544 has been patched. Fixed versions include 7.1.8 and 7.2. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-74544 actively exploited?

CVE-2026-74544 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-74544

High

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().

Package Linux Kernel

Published 2026-08-15

Last modified 2026-08-17

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 2.6.12 and later are affected. Fixed in 7.1.8, 7.2 and their respective stable series.

Affected from

≥ 2.6.12

Fixed in

✓ 7.1.8 7.1.x ✓ 7.2

References

2 total

Details

CVE ID CVE-2026-74544

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2026-08-15

Modified 2026-08-17

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-74544?

CVE-2026-74544 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 2.6.12 onward and has been patched in 7.1.8 and 7.2. CVE-2026-74544 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-74544?

CVE-2026-74544 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-74544?

Yes. CVE-2026-74544 has been patched. Fixed versions include 7.1.8 and 7.2. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-74544 actively exploited?

No. CVE-2026-74544 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.