Vulnerability · Published May 1, 2026 · Assigned by Linux

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

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.2%top 95.3% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official 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

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linuxno fix listedDEBIAN-CVE-2026-43036
Debian:13linux6.12.85-1DEBIAN-CVE-2026-43036
Debian:14linux6.19.12-1DEBIAN-CVE-2026-43036
Ubuntu:22.04:LTSlinuxno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux6.8.0-136.136UBUNTU-CVE-2026-43036
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-aws6.8.0-1061.64UBUNTU-CVE-2026-43036
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1061.64~22.04.1UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-azure6.8.0-1063.71UBUNTU-CVE-2026-43036
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1063.71~22.04.1UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1062.69UBUNTU-CVE-2026-43036
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1062.69~22.04.1UBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-gcp6.8.0-1064.72UBUNTU-CVE-2026-43036
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1064.72~22.04.1UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-gke6.8.0-1059.67UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1046.50UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-136.136~22.04.1UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-ibm6.8.0-1061.62UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1061.62~22.04.1UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-intel-iotgno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-kvmno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-136.136.2UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-136.136.2~22.04.1UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1059.62UBUNTU-CVE-2026-43036
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1006.6UBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1059.62~22.04.1UBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1059.62.1UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-nvidia-tegrano fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1030.31UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-nvidia-tegra-igxno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-oracle6.8.0-1058.61UBUNTU-CVE-2026-43036
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1058.61~22.04.1UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-raspi6.8.0-1061.65UBUNTU-CVE-2026-43036
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-43036
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-43036
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-136.136~22.04.3UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-vmware6.8.0-1008.8UBUNTU-CVE-2026-43036
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1033.34UBUNTU-CVE-2026-43036
Ubuntu:22.04:LTSlinux-xilinx-zynqmpno fix listedUBUNTU-CVE-2026-43036

Affected products (as reported)

VendorProductVersions
Linux Linux cbc53e08a793b073e79f42ca33f1f3568703540d – before 362bacb37d88a178bfaefc4484623eae44425a70cbc53e08a793b073e79f42ca33f1f3568703540d – before 5057502630fbc8ce468ff617ff59af275960b537cbc53e08a793b073e79f42ca33f1f3568703540d – before f7a6cd508e9e825a2c69fa9e13d41ee156852f25cbc53e08a793b073e79f42ca33f1f3568703540d – before cc91202fc20a44aab4c206f12a2bfe05da936051cbc53e08a793b073e79f42ca33f1f3568703540d – before d970341cfa5594614c7a6634886c7688b4f5cafdcbc53e08a793b073e79f42ca33f1f3568703540d – before ddc748a391dd8642ba6b2e4fe22e7f2ddf84b7f0
Linux Linux 4.7

References