Medium 5.5Published May 1, 2026

CVE-2026-43036net: use skb_header_pointer() for TCPv4 GSO frag_off check

Updated under an hour ago (Oct 27, 2026, 8:30 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 21, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from cbc53e08a793b073e79f42ca33f1f3568703540d before 5057502630fbc8ce468ff617ff59af275960b537; from cbc53e08a793b073e79f42ca33f1f3568703540d before f7a6cd508e9e825a2c69fa9e13d41ee156852f25; from cbc53e08a793b073e79f42ca33f1f3568703540d before cc91202fc20a44aab4c206f12a2bfe05da936051; from cbc53e08a793b073e79f42ca33f1f3568703540d before d970341cfa5594614c7a6634886c7688b4f5cafd; from cbc53e08a793b073e79f42ca33f1f3568703540d before ddc748a391dd8642ba6b2e4fe22e7f2ddf84b7f0	CNA record
linux linux_kernel linux:linux_kernel	from 4.7 before 6.12.81; from 6.13 before 6.18.22; from 6.19 before 6.19.12; 7.0; 7.0; 7.0; 7.0; 7.0; and 1 more ranges	NVD

References

References

https://git.kernel.org/stable/c/5057502630fbc8ce468ff617ff59af275960b537
https://git.kernel.org/stable/c/f7a6cd508e9e825a2c69fa9e13d41ee156852f25	patch
https://git.kernel.org/stable/c/cc91202fc20a44aab4c206f12a2bfe05da936051	patch
https://git.kernel.org/stable/c/d970341cfa5594614c7a6634886c7688b4f5cafd	patch
https://git.kernel.org/stable/c/ddc748a391dd8642ba6b2e4fe22e7f2ddf84b7f0	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.