{"id":"CVE-2026-98096","summary":"ipv6: sr: restore network header before routing and forwarding","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: sr: restore network header before routing and forwarding\n\nipv6_srh_rcv() runs with skb-\u003edata at the Segment Routing Header (SRH)\nwhile skb_network_header() points at the IPv6 header.\n\nWhen segments_left \u003e 0, ipv6_srh_rcv() previously restored the skb-\u003edata\nposition by pushing sizeof(struct ipv6hdr), assuming the SRH immediately\nfollowed the fixed IPv6 header. If another extension header (such as a\nHop-by-Hop options header) precedes the SRH, skb_network_offset()\nremained negative.\n\nThis led to two problems:\n1. During ip6_route_input(), fib6_rules_early_flow_dissect() invokes\n   __skb_flow_dissect() which passes the negative skb_network_offset()\n   to flow dissection, breaking BPF and C flow dissector logic.\n2. If forwarded via ip6_forward() or redirected via act_mirred, downstream\n   handlers (like sch_fragment() or neighbour output) pass the negative\n   offset as an unsigned length, triggering OOB memcpy or buffer overflows.\n\nFix this by pushing -skb_network_offset(skb) before routing, ensuring\nskb_network_offset(skb) is 0 for route lookup / flow dissection as well as\ndownstream forwarding. On the loopback path, pull skb_transport_offset(skb)\nto restore skb-\u003edata to the SRH before looping back.","modified":"2026-09-26T03:48:32.581345369Z","published":"2026-09-25T10:24:27.098Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98096.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3ad7dca5e03bd64c65983a19734337512fd75491"},{"type":"WEB","url":"https://git.kernel.org/stable/c/975b5b067f525a1b1338c4a3bee1c46545801518"},{"type":"WEB","url":"https://git.kernel.org/stable/c/97b21ef57dfabbff660a4672c9fef7edfb720f47"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ce4c8beedc19aceeab0e7bdc6f34394fb158c47c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98096.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98096"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"1ababeba4a21f3dba3da3523c670b207fb2feb62"},{"fixed":"ce4c8beedc19aceeab0e7bdc6f34394fb158c47c"},{"fixed":"97b21ef57dfabbff660a4672c9fef7edfb720f47"},{"fixed":"3ad7dca5e03bd64c65983a19734337512fd75491"},{"fixed":"975b5b067f525a1b1338c4a3bee1c46545801518"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98096.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.10.0"},{"fixed":"6.12.111"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.53"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98096.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H"}]}