{"id":"CVE-2026-53228","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-53228","summary":"ipv6: sit: reload inner IPv6 header after GSO offloads","details":"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.","published":"2026-06-25T08:39:27.893Z","modified":"2026-08-12T03:51:33.093293434Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":{"score":0.00514,"percentile":0.40971,"asOf":"2026-08-06"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"5.10.259"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1132e5edc2866c3530be17622153a597095f0e43"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2fa49b2715e1bad12ce3b0fa64e234d9582c8193"},{"type":"WEB","url":"https://git.kernel.org/stable/c/59f80c919713250fe5d25a4d9aea4e49580fa1d4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9c67b44edb3598d234efae6e44649eb993c03da5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f0e42f0c4337b1f220de1ddd63f47197c7dee4de"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fddd41445a0537b093e6b3f6232c9933cad1e48b"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53228.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53228"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:33.093293434Z"}}