What is CVE-2026-43036?

CVE-2026-43036 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 4.7 onward and patched in 6.12.81, 6.18.22, 6.19.12 and others. CVE-2026-43036 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43036?

CVE-2026-43036 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-43036?

Yes, CVE-2026-43036 has been patched. Fixed versions include 6.12.81, 6.18.22, 6.19.12 and others. If you are running Linux kernel 4.7 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43036 actively exploited?

CVE-2026-43036 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-43036

Medium

In the Linux kernel, the following vulnerability has been resolved: net: use skb_header_pointer() for TCPv4 GSO frag_off check Syzbot reported a KMSAN uninit-value warning in gso_features_check() called from netif_skb_features() [1]. gso_features_check() reads iph->frag_off to decide whether to clear mangleid_features. Accessing the IPv4 header via ip_hdr()/inner_ip_hdr() can rely on skb header offsets that are not always safe for direct dereference on packets injected from PF_PACKET paths. Use skb_header_pointer() for the TCPv4 frag_off check so the header read is robust whether data is already linear or needs copying. [1] https://syzkaller.appspot.com/bug?extid=1543a7d954d9c6d00407

Package Linux Kernel

Published 2026-05-01

Last modified 2026-05-08

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-908

CVE-2026-43036 is classified as CWE-908

See CWE-908 on MITRE CWE for full details on this weakness type.

Affected versions

Linux kernel versions 4.7 and later are affected. Fixed in 6.12.81, 6.18.22, 6.19.12, 7.0 and their respective stable series.

Affected from

≥ 4.7

Fixed in

✓ 6.12.81 6.12.x ✓ 6.18.22 6.18.x ✓ 6.19.12 6.19.x ✓ 7.0

References

4 total

Kernel Git
https://git.kernel.org/stable/c/cc91202fc20a44aab4c206f12a2bfe05da936051

Patch
Kernel Git
https://git.kernel.org/stable/c/d970341cfa5594614c7a6634886c7688b4f5cafd

Patch
Kernel Git
https://git.kernel.org/stable/c/ddc748a391dd8642ba6b2e4fe22e7f2ddf84b7f0

Patch
Kernel Git
https://git.kernel.org/stable/c/f7a6cd508e9e825a2c69fa9e13d41ee156852f25

Patch

Details

CVE ID CVE-2026-43036

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-05-01

Modified 2026-05-08

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43036?

CVE-2026-43036 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 4.7 onward and has been patched in 6.12.81, 6.18.22, 6.19.12 and others. CVE-2026-43036 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43036?

CVE-2026-43036 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-43036?

Yes. CVE-2026-43036 has been patched. Fixed versions include 6.12.81, 6.18.22, 6.19.12 and others. If you are running Linux kernel 4.7 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43036 actively exploited?

No. CVE-2026-43036 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.