{"id":"CVE-2026-72250","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-72250","generatedAt":"2026-10-28T03:29:18.277Z","title":"In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_reasm: guard mac_header adjustment after IPv6 defrag nf_ct_frag6_reasm() slides the packet head forward to drop the IPv6 fragment header and then unconditionally…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_reasm: guard mac_header adjustment after IPv6 defrag\n\nnf_ct_frag6_reasm() slides the packet head forward to drop the IPv6\nfragment header and then unconditionally advances skb->mac_header:\n\n\tskb->mac_header += sizeof(struct frag_hdr);\n\nOn the NF_INET_LOCAL_OUT defrag path the skb has no link-layer header\nyet, so skb->mac_header is still the \"not set\" sentinel (u16)~0U. Adding\nsizeof(struct frag_hdr) wraps it to a small value (0xffff + 8 == 7),\nafter which skb_mac_header_was_set() wrongly reports a MAC header is\npresent and skb_mac_header() points into the headroom.\n\nThe reassembler has done this unconditional add since it was introduced;\nit was harmless while mac_header was a bare pointer, but wrong once\nmac_header became a u16 offset whose unset state is the ~0U sentinel\ntested by skb_mac_header_was_set(). The sibling net/ipv6/reassembly.c\ndoes the same relocation and does guard the adjustment; mirror the\nguard here.","published":"2026-08-15T06:21:52.000Z","lastModified":"2026-10-16T19:17:17.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":[],"affected":[],"epss":{"score":0.00169,"percentile":0.06199,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/00bdce2fda7e430d24cfbc96764a1b96deb31f82","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2a95ec21824a8ad81ad660b12231456fc0ac9830","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3b08fed5b7e0d5e3a25d73ef3ba09cd33ade16c9","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/53ef70a315420ed31581d38343684b3bf9a3c76d","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6e8cd710ca35c576f5f2e5a396047c9ac61f75e5","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a58230f3a7c4f6c3261786bc1efb72c42e68cd25","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bbcdef2061b170af45702ce6b359c02c12acfc94","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cd0d7bbc027b4d3329712cdcdeb4e5567ffd0d58","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-72250","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}