{"id":"CVE-2026-53228","state":"PUBLISHED","title":"ipv6: sit: reload inner IPv6 header after GSO offloads","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: sit: reload inner IPv6 header after GSO offloads\n\nipip6_tunnel_xmit() caches the inner IPv6 header pointer at function\nentry and continues using it after iptunnel_handle_offloads().\n\nFor GSO skbs, iptunnel_handle_offloads() calls skb_header_unclone().\nWhen the skb header is cloned, skb_header_unclone() can call\npskb_expand_head(), which may move the skb head. The pskb_expand_head()\ncontract requires pointers into the skb header to be reloaded after the\ncall.\n\nIf the later skb_realloc_headroom() branch is not taken, SIT uses the\nstale iph6 pointer to read the inner hop limit and DS field. That can\nread from a freed skb head after the old head's remaining clone is\nreleased.\n\nReload iph6 after the offload helper succeeds and before subsequent\nreads from the inner IPv6 header. Keep the existing reload after\nskb_realloc_headroom(), since that branch can also replace the skb.","publishedAt":"2026-06-25T08:39:27.893Z","updatedAt":"2026-10-19T19:57:30.192Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"fddd41445a0537b093e6b3f6232c9933cad1e48b","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"1132e5edc2866c3530be17622153a597095f0e43","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"9c67b44edb3598d234efae6e44649eb993c03da5","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"59f80c919713250fe5d25a4d9aea4e49580fa1d4","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"2fa49b2715e1bad12ce3b0fa64e234d9582c8193","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"f0e42f0c4337b1f220de1ddd63f47197c7dee4de","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/sit.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.18","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/sit.c"]}],"references":["https://git.kernel.org/stable/c/fddd41445a0537b093e6b3f6232c9933cad1e48b","https://git.kernel.org/stable/c/1132e5edc2866c3530be17622153a597095f0e43","https://git.kernel.org/stable/c/9c67b44edb3598d234efae6e44649eb993c03da5","https://git.kernel.org/stable/c/0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0","https://git.kernel.org/stable/c/59f80c919713250fe5d25a4d9aea4e49580fa1d4","https://git.kernel.org/stable/c/2fa49b2715e1bad12ce3b0fa64e234d9582c8193","https://git.kernel.org/stable/c/cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c","https://git.kernel.org/stable/c/f0e42f0c4337b1f220de1ddd63f47197c7dee4de","https://cert-portal.siemens.com/productcert/html/ssa-784472.html"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53228.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53228","state":"PUBLISHED","datePublished":"2026-06-25T08:39:27.893Z","dateUpdated":"2026-10-19T19:57:30.192Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.393Z"},"containers":{"cna":{"title":"ipv6: sit: reload inner IPv6 header after GSO offloads","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: sit: reload inner IPv6 header after GSO offloads\n\nipip6_tunnel_xmit() caches the inner IPv6 header pointer at function\nentry and continues using it after iptunnel_handle_offloads().\n\nFor GSO skbs, iptunnel_handle_offloads() calls skb_header_unclone().\nWhen the skb header is cloned, skb_header_unclone() can call\npskb_expand_head(), which may move the skb head. The pskb_expand_head()\ncontract requires pointers into the skb header to be reloaded after the\ncall.\n\nIf the later skb_realloc_headroom() branch is not taken, SIT uses the\nstale iph6 pointer to read the inner hop limit and DS field. That can\nread from a freed skb head after the old head's remaining clone is\nreleased.\n\nReload iph6 after the offload helper succeeds and before subsequent\nreads from the inner IPv6 header. Keep the existing reload after\nskb_realloc_headroom(), since that branch can also replace the skb."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"fddd41445a0537b093e6b3f6232c9933cad1e48b","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"1132e5edc2866c3530be17622153a597095f0e43","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"9c67b44edb3598d234efae6e44649eb993c03da5","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"59f80c919713250fe5d25a4d9aea4e49580fa1d4","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"2fa49b2715e1bad12ce3b0fa64e234d9582c8193","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c","versionType":"git"},{"version":"14909664e4e192f4c6f6fcdccd9919af7cf783ab","status":"affected","lessThan":"f0e42f0c4337b1f220de1ddd63f47197c7dee4de","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/sit.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.18","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/sit.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/fddd41445a0537b093e6b3f6232c9933cad1e48b"},{"url":"https://git.kernel.org/stable/c/1132e5edc2866c3530be17622153a597095f0e43"},{"url":"https://git.kernel.org/stable/c/9c67b44edb3598d234efae6e44649eb993c03da5"},{"url":"https://git.kernel.org/stable/c/0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0"},{"url":"https://git.kernel.org/stable/c/59f80c919713250fe5d25a4d9aea4e49580fa1d4"},{"url":"https://git.kernel.org/stable/c/2fa49b2715e1bad12ce3b0fa64e234d9582c8193"},{"url":"https://git.kernel.org/stable/c/cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c"},{"url":"https://git.kernel.org/stable/c/f0e42f0c4337b1f220de1ddd63f47197c7dee4de"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable SIT transmit path can be reached by network-triggered IPv6 traffic in a reasonable deployment where a public service or router sends large TCP/GSO packets through a configured SIT tunnel.\nAC:L - There is no race or fragile timing requirement; GSO and header-cloned TCP skbs are normal for large TCP transmissions, and the attacker can repeatedly trigger them with network traffic.\nPR:N - In the network-triggered scenario, the attacker does not need local privileges or authentication; the required SIT configuration is an environmental precondition on the victim.\nUI:N - No victim user action is required beyond the system processing network traffic through the configured SIT tunnel.\nS:U - The impact remains within the kernel and its networking security authority, with no VM, IOMMU, or separate security-scope boundary crossed.\nC:H - The stale inner IPv6 header pointer can read from freed skb head memory after `skb_header_unclone()`/`pskb_expand_head()`, making this a kernel use-after-free read. Per kernel CVSS guidance, use-after-free conditions are scored with high confidentiality impact.\nI:H - Although the immediate stale access feeds header fields, it is a kernel use-after-free in attacker-triggerable networking memory, and kernel UAFs are treated as potentially exploitable for heap manipulation and integrity compromise.\nA:H - Use-after-free in the kernel networking transmit path can lead to oops, panic, or repeated crash conditions, especially under memory debugging or unfavorable heap reuse."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:34:20.273Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.18","versionEndExcluding":"5.10.259"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.18","versionEndExcluding":"5.15.210"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.18","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.18","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.18","versionEndExcluding":"6.12.94"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.18","versionEndExcluding":"6.18.36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.18","versionEndExcluding":"7.0.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.18","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 TM MFP - GNU/Linux subsystem","defaultStatus":"unknown","versions":[{"version":"0","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:22:51.790Z"},"x_adpType":"supplier"},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-53228","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:27:17.714387Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:57:30.192Z"}}]}}}