VDB

CVE-2026-43057

CVE-2026-43057 PUBLISHED CVSS 7.5 HIGH

net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback

Reported by linux · Published May 1, 2026

In the Linux kernel, the following vulnerability has been resolved: net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback NETIF_F_IPV6_CSUM only advertises support for checksum offload of packets without IPv6 extension headers. Packets with extension headers must fall back onto software checksumming. Since TSO depends on checksum offload, those must revert to GSO. The below commit introduces that fallback. It always checks network header length. For tunneled packets, the inner header length must be checked instead. Extend the check accordingly. A special case is tunneled packets without inner IP protocol. Such as RFC 6951 SCTP in UDP. Those are not standard IPv6 followed by transport header either, so also must revert to the software GSO path.

Fixed versions

Upgrade to a fixed version or later. Language registries are listed first, then Linux distributions, then vendor products.

PackageEcosystemFixed in
kernel6.18-toolsAmazon Linux1:6.18.25-52.107.amzn2023
kernel-libbpf-staticAmazon Linux1:6.1.168-202.320.amzn2023
kernel-livepatch-6.1.168-202.320Amazon Linux1:1.0-0.amzn2023
kernel-livepatch-6.18.25-52.107Amazon Linux1:1.0-0.amzn2023
perfAmazon Linux1:6.1.168-202.320.amzn2023
kernel-modules-extra-commonAmazon Linux1:6.1.168-202.320.amzn2023
kernel6.12-modules-extra-commonAmazon Linux1:6.12.83-113.160.amzn2023
kernel-develAmazon Linux1:6.1.168-202.320.amzn2023
kernel6.18Amazon Linux1:6.18.25-52.107.amzn2023
linux_kernellinux6.19.12, 6.18.22, 6.17, 6.12.81, 6.6.134, 6.1.168

Risk scores

CVSS 3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

VendorProductVersions
LinuxLinuxa0478d7e888028f85fa7785ea838ce0ca09398e2, 2156d9e9f2e483c8c3906c0ea57ea312c1424235, 041e2f945f82fdbd6fff577b79c33469430297aa
LinuxLinux6.17, 0, 6.1.168
amazon:2023kernel6.18-tools0
amazon:2023kernel-libbpf-static0
amazon:2023kernel-livepatch-6.1.168-202.3200
amazon:2023kernel-livepatch-6.18.25-52.1070
amazon:2023perf0
amazon:2023kernel-modules-extra-common0
SiemensSIPLUS S7-1500 CPU 1518-4 PN/DP MFP3.1.7, 3.1.6, 3.1.5
amazon:2023kernel6.12-modules-extra-common0
amazon:2023kernel-devel0
amazon:2023kernel6.180
amazon:2023python3-perf0
amazon:2023kernel6.18-headers0
amazon:2023kernel6.12-tools-devel0
amazon:2023kernel6.120
amazon:2023python3-perf6.120
amazon:2023kernel6.12-headers0
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP3.1.6, 3.1.5, 3.1.7
amazon:2023kernel6.18-modules-extra-common0

…and 23 more

Timeline

  • May 1, 2026 CVE Published
  • May 18, 2026 EPSS Score (30 in total, the first dated here)
  • Jun 2, 2026 Security Advisory (120 in total, the first dated here)
  • Jul 28, 2026 Coalition ESS Score
  • Aug 11, 2026 Distribution Patch (114 in total, the first dated here)

Query this with the API

The same record, from the CLI:

vulnetix vdb vuln CVE-2026-43057
vulnetix vdb fixes CVE-2026-43057

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curl -s -H "Authorization: ApiKey ${VULNETIX_ORG_ID}:${VULNETIX_API_KEY}" \
  "https://api.vdb.vulnetix.com/v2/vuln/CVE-2026-43057/fixes/registry"

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References

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