{"id":"CVE-2026-63994","summary":"tunnels: load network headers after skb_cow() in iptunnel_pmtud_build_icmp[v6]()","details":"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-\u003ehead.\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.","modified":"2026-10-28T02:31:02.721793811Z","published":"2026-07-19T14:56:13.896Z","related":["ALSA-2026:75746","ALSA-2026:75747","ALSA-2026:76738","SUSE-SU-2026:23066-1","SUSE-SU-2026:23068-1","SUSE-SU-2026:23193-1","SUSE-SU-2026:23194-1","SUSE-SU-2026:23221-1","SUSE-SU-2026:23231-1","SUSE-SU-2026:23237-1","SUSE-SU-2026:23241-1","SUSE-SU-2026:23244-1","SUSE-SU-2026:23994-1","SUSE-SU-2026:23995-1","SUSE-SU-2026:23996-1","SUSE-SU-2026:23997-1","SUSE-SU-2026:23998-1","SUSE-SU-2026:23999-1","SUSE-SU-2026:24000-1","SUSE-SU-2026:24001-1","SUSE-SU-2026:24002-1","SUSE-SU-2026:24003-1","SUSE-SU-2026:24004-1","SUSE-SU-2026:24005-1","SUSE-SU-2026:24006-1","SUSE-SU-2026:24007-1","SUSE-SU-2026:24008-1","SUSE-SU-2026:24009-1","SUSE-SU-2026:24010-1","SUSE-SU-2026:24016-1","SUSE-SU-2026:24023-1","SUSE-SU-2026:24024-1","SUSE-SU-2026:24025-1","SUSE-SU-2026:24026-1","SUSE-SU-2026:24027-1","SUSE-SU-2026:24028-1","SUSE-SU-2026:24029-1","SUSE-SU-2026:24030-1","SUSE-SU-2026:24031-1","SUSE-SU-2026:24032-1","SUSE-SU-2026:24033-1","SUSE-SU-2026:24034-1","SUSE-SU-2026:24035-1","SUSE-SU-2026:24036-1","SUSE-SU-2026:24037-1","SUSE-SU-2026:24038-1","SUSE-SU-2026:24041-1","SUSE-SU-2026:24042-1","SUSE-SU-2026:24043-1","SUSE-SU-2026:24044-1","SUSE-SU-2026:24045-1","SUSE-SU-2026:24046-1","SUSE-SU-2026:24047-1","SUSE-SU-2026:24048-1","SUSE-SU-2026:24049-1","SUSE-SU-2026:24050-1","SUSE-SU-2026:24051-1","SUSE-SU-2026:24052-1","SUSE-SU-2026:24053-1","SUSE-SU-2026:24054-1","SUSE-SU-2026:24059-1","SUSE-SU-2026:24060-1","SUSE-SU-2026:24061-1","SUSE-SU-2026:24062-1","SUSE-SU-2026:24063-1","SUSE-SU-2026:24064-1","SUSE-SU-2026:24065-1","SUSE-SU-2026:24066-1","SUSE-SU-2026:24067-1","SUSE-SU-2026:24068-1","SUSE-SU-2026:24069-1","SUSE-SU-2026:24070-1","SUSE-SU-2026:24071-1","SUSE-SU-2026:24072-1","SUSE-SU-2026:24075-1","SUSE-SU-2026:24076-1","SUSE-SU-2026:24077-1","SUSE-SU-2026:24078-1","SUSE-SU-2026:24079-1","SUSE-SU-2026:24080-1","SUSE-SU-2026:24081-1","SUSE-SU-2026:24082-1","SUSE-SU-2026:24083-1","SUSE-SU-2026:24084-1","SUSE-SU-2026:24085-1","SUSE-SU-2026:24086-1","SUSE-SU-2026:24087-1","SUSE-SU-2026:24088-1","SUSE-SU-2026:24089-1","SUSE-SU-2026:24090-1","SUSE-SU-2026:24092-1","SUSE-SU-2026:24093-1","SUSE-SU-2026:24095-1","SUSE-SU-2026:24097-1","SUSE-SU-2026:24098-1","SUSE-SU-2026:24099-1","SUSE-SU-2026:24100-1","SUSE-SU-2026:24101-1","SUSE-SU-2026:24102-1","SUSE-SU-2026:24103-1","SUSE-SU-2026:24104-1","SUSE-SU-2026:24105-1","SUSE-SU-2026:24106-1","SUSE-SU-2026:24107-1","SUSE-SU-2026:24108-1","SUSE-SU-2026:24160-1","SUSE-SU-2026:24161-1","SUSE-SU-2026:24163-1","SUSE-SU-2026:24164-1","SUSE-SU-2026:24165-1","SUSE-SU-2026:24166-1","SUSE-SU-2026:24167-1","SUSE-SU-2026:24168-1","SUSE-SU-2026:24169-1","SUSE-SU-2026:24170-1","SUSE-SU-2026:24171-1","SUSE-SU-2026:24172-1","SUSE-SU-2026:24173-1","SUSE-SU-2026:24174-1","SUSE-SU-2026:24175-1","SUSE-SU-2026:3593-1","SUSE-SU-2026:3595-1","SUSE-SU-2026:3602-1","SUSE-SU-2026:3616-1","SUSE-SU-2026:3617-1","SUSE-SU-2026:3790-1","SUSE-SU-2026:3810-1","SUSE-SU-2026:4415-1","SUSE-SU-2026:4471-1","SUSE-SU-2026:4489-1","SUSE-SU-2026:4498-1","SUSE-SU-2026:4507-1","SUSE-SU-2026:4513-1","SUSE-SU-2026:4516-1","SUSE-SU-2026:4518-1","SUSE-SU-2026:4519-1","SUSE-SU-2026:4537-1","openSUSE-SU-2026:21555-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63994.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/50750d86a2e5266aba0c295483b3397843198b11"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6dff77899b9e9fe5d854abda3a98ad04e7229ef7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7254aef4d1a7e18e887af9010e2f2dc34806789b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/76cd9398a0470257ab765bdf5f358a2af2e17934"},{"type":"WEB","url":"https://git.kernel.org/stable/c/95b6d772bfe788331d9742d73eaa12e113b2adc4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b4bc94353050b1fa7b702bd4c6600710dd926cff"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bf8b3f34c37c162357138e7c0942723b8b94fed1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f3f204541f280a6ecb04503a0d6794d93990ca43"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63994.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63994"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f"},{"fixed":"95b6d772bfe788331d9742d73eaa12e113b2adc4"},{"fixed":"7254aef4d1a7e18e887af9010e2f2dc34806789b"},{"fixed":"bf8b3f34c37c162357138e7c0942723b8b94fed1"},{"fixed":"76cd9398a0470257ab765bdf5f358a2af2e17934"},{"fixed":"50750d86a2e5266aba0c295483b3397843198b11"},{"fixed":"6dff77899b9e9fe5d854abda3a98ad04e7229ef7"},{"fixed":"f3f204541f280a6ecb04503a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