{"id":"CVE-2026-63994","revision":"1143e60a18444ed384ad70f3aa4a0844","records":[{"revision":"1143e60a18444ed384ad70f3aa4a0844","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-63994","aliases":[],"title":"tunnels: load network headers after skb_cow() in iptunnel_pmtud_build_icmp[v6]()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntunnels: load network headers after skb_cow() in iptunnel_pmtud_build_icmp[v6]()\n\nSashiko found that iptunnel_pmtud_build_icmp() and\niptunnel_pmtud_build_icmpv6() were caching ip_hdr() and ipv6_hdr()\nbefore an skb_cow() call which can reallocate skb->head.\n\nFix this possible UAF by initializing the local variables\nafter the skb_cow() call.\n\nRemove skb_reset_network_header() calls which were not needed.","state":0,"publishedAt":"2026-07-19T14:56:13.896+00:00","modifiedAt":"2026-10-19T20:18:01.494+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv4/ip_tunnel_core.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4cb47a8644cc9eb8ec81190a50e79e6530d0297f\",\n                            \"lessThan\": \"95b6d772bfe788331d9742d73eaa12e113b2adc4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4cb47a8644cc9eb8ec81190a50e79e6530d0297f\",\n                            \"lessThan\": \"7254aef4d1a7e18e887af9010e2f2dc34806789b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4cb47a8644cc9eb8ec81190a50e79e6530d0297f\",\n                            \"lessThan\": \"bf8b3f34c37c162357138e7c0942723b8b94fed1\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4cb47a8644cc9eb8ec81190a50e79e6530d0297f\",\n                            \"lessThan\": \"76cd9398a0470257ab765bdf5f358a2af2e17934\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4cb47a8644cc9eb8ec81190a50e79e6530d0297f\",\n                            \"lessThan\": \"50750d86a2e5266aba0c295483b3397843198b11\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4cb47a8644cc9eb8ec81190a50e79e6530d0297f\",\n                            \"lessThan\": \"6dff77899b9e9fe5d854abda3a98ad04e7229ef7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4cb47a8644cc9eb8ec81190a50e79e6530d0297f\",\n                            \"lessThan\": \"f3f204541f280a6ecb04503a0d6794d93990ca43\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4cb47a8644cc9eb8ec81190a50e79e6530d0297f\",\n                            \"lessThan\": \"b4bc94353050b1fa7b702bd4c6600710dd926cff\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv4/ip_tunnel_core.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.9\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.9\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.259\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.210\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.176\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.143\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.93\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.35\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.12\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/95b6d772bfe788331d9742d73eaa12e113b2adc4","https://git.kernel.org/stable/c/7254aef4d1a7e18e887af9010e2f2dc34806789b","https://git.kernel.org/stable/c/bf8b3f34c37c162357138e7c0942723b8b94fed1","https://git.kernel.org/stable/c/76cd9398a0470257ab765bdf5f358a2af2e17934","https://git.kernel.org/stable/c/50750d86a2e5266aba0c295483b3397843198b11","https://git.kernel.org/stable/c/6dff77899b9e9fe5d854abda3a98ad04e7229ef7","https://git.kernel.org/stable/c/f3f204541f280a6ecb04503a0d6794d93990ca43","https://git.kernel.org/stable/c/b4bc94353050b1fa7b702bd4c6600710dd926cff"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-63994","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-63994","identifiers":["CVE-2026-63994"]},"retained":false,"historicalAffected":[]}],"coverage":[]}