What is CVE-2025-40337?

CVE-2025-40337 is a High severity Linux kernel vulnerability with a CVSS score of 8.2 out of 10, affecting Linux kernel versions from 3.2 onward and patched in 6.6.117, 6.12.58, 6.17.8 and others. CVE-2025-40337 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-40337?

CVE-2025-40337 has a CVSS score of 8.2 out of 10, rated High severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L.

Is there a patch available for CVE-2025-40337?

Yes, CVE-2025-40337 has been patched. Fixed versions include 6.6.117, 6.12.58, 6.17.8 and others. If you are running Linux kernel 3.2 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-40337 actively exploited?

CVE-2025-40337 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-40337

High

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: Correctly handle Rx checksum offload errors The stmmac_rx function would previously set skb->ip_summed to CHECKSUM_UNNECESSARY if hardware checksum offload (CoE) was enabled and the packet was of a known IP ethertype. However, this logic failed to check if the hardware had actually reported a checksum error. The hardware status, indicating a header or payload checksum failure, was being ignored at this stage. This could cause corrupt packets to be passed up the network stack as valid. This patch corrects the logic by checking the `csum_none` status flag, which is set when the hardware reports a checksum error. If this flag is set, skb->ip_summed is now correctly set to CHECKSUM_NONE, ensuring the kernel's network stack will perform its own validation and properly handle the corrupt packet.

Package Linux Kernel

Published 2025-12-09

Last modified 2026-07-30

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

8.2

out of 10

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

High

Availability

Low

Vector string

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

Affected versions

Linux kernel versions 3.2 and later are affected. Fixed in 6.6.117, 6.12.58, 6.17.8, 6.18 and their respective stable series.

Affected from

≥ 3.2

Fixed in

✓ 6.6.117 6.6.x ✓ 6.12.58 6.12.x ✓ 6.17.8 6.17.x ✓ 6.18

References

4 total

Details

CVE ID CVE-2025-40337

Severity High

CVSS score 8.2 / 10

CVSS version 3.1

Published 2025-12-09

Modified 2026-07-30

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-40337?

CVE-2025-40337 is a High severity Linux kernel vulnerability with a CVSS score of 8.2 out of 10 . It affects Linux kernel versions from 3.2 onward and has been patched in 6.6.117, 6.12.58, 6.17.8 and others. CVE-2025-40337 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-40337?

CVE-2025-40337 has a CVSS score of 8.2 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L.
Is there a patch available for CVE-2025-40337?

Yes. CVE-2025-40337 has been patched. Fixed versions include 6.6.117, 6.12.58, 6.17.8 and others. If you are running Linux kernel 3.2 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-40337 actively exploited?

No. CVE-2025-40337 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.