Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2026-43036

5.5 · 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()…

Published May 1, 2026CWE-908EPSS 0.12%

Overview

CVE-2026-43036 is a medium-severity vulnerability. It was published on May 1, 2026 and has a CVSS 3.1 base score of 5.5 (MEDIUM).

This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.

Technical description

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

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refgit.kernel.org/stable/c/cc91202fc20a44aab4c206f12a2bfe05da936051Refgit.kernel.org/stable/c/d970341cfa5594614c7a6634886c7688b4f5cafdRefgit.kernel.org/stable/c/ddc748a391dd8642ba6b2e4fe22e7f2ddf84b7f0Refgit.kernel.org/stable/c/f7a6cd508e9e825a2c69fa9e13d41ee156852f25

How CyberStrike helps

Frequently asked questions

What is CVE-2026-43036?

CVE-2026-43036 is a medium-severity vulnerability. It was published on May 1, 2026 and has a CVSS 3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2026-43036?

This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.

How do I fix or remediate CVE-2026-43036?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-43036?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-43036 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related MEDIUM CVEs from 2026

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999