{"id":"CVE-2026-68299","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-68299","summary":"vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nvmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets\n\nvmxnet3_get_hdr_len() assumes gdesc->rcd.v4/v6/tcp always describe the\nouter header, but for a Geneve-encapsulated packet the device can set\nthem based on the inner header instead, signalled by the\nVMXNET3_RCD_HDR_INNER_SHIFT bit in the completion descriptor. Since the\nfunction never skips the outer encapsulation, this mismatch triggers:\n\n- BUG_ON(hdr.ipv4->protocol != IPPROTO_TCP), because the outer\n  protocol is UDP (Geneve), not TCP.\n- BUG_ON(hdr.eth->h_proto != ...), when the tunnel's outer and inner\n  IP versions differ (e.g. outer IPv6/inner IPv4 or vice versa).\n\nCheck VMXNET3_RCD_HDR_INNER_SHIFT up front and bail out, since the\nfunction cannot locate the inner header it would need to parse. Also\nconvert the remaining BUG_ON()s in this function to return 0\ndefensively.","published":"2026-08-10T12:02:33.213Z","modified":"2026-08-14T04:04:01.104652441Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.6.148"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/34a71f5361fc3adb5b7138da78750b0d535a8252"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4fdb0f162ccdbe9626863b10003855703253fa29"},{"type":"WEB","url":"https://git.kernel.org/stable/c/667b6e52048eaf4dbcf1707ed87ffd44abb9cb38"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b28596baf87e25a078789f1c05817c8a3bf71257"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68299.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68299"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-14T04:04:01.104652441Z"}}