{"id":"CVE-2026-98096","published":"2026-09-25T11:17:39.373","lastModified":"2026-09-25T15:18:05.827","description":"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->data at the Segment Routing Header (SRH)\nwhile skb_network_header() points at the IPv6 header.\n\nWhen segments_left > 0, ipv6_srh_rcv() previously restored the skb->data\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->data to the SRH before looping back.","cvssScore":7.4,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/3ad7dca5e03bd64c65983a19734337512fd75491","tags":[]},{"url":"https://git.kernel.org/stable/c/975b5b067f525a1b1338c4a3bee1c46545801518","tags":[]},{"url":"https://git.kernel.org/stable/c/97b21ef57dfabbff660a4672c9fef7edfb720f47","tags":[]},{"url":"https://git.kernel.org/stable/c/ce4c8beedc19aceeab0e7bdc6f34394fb158c47c","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}