{"id":"CVE-2026-68299","state":"PUBLISHED","title":"vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets","description":"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.","publishedAt":"2026-08-10T12:02:33.213Z","updatedAt":"2026-10-19T21:09:04.053Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"2ddf51fcb6dd7d55ceef38e2e1a5ab2ab7fd47b0","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"fbab6b73cc086e32698c86e43d1b16bf17d24c36","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"28e382646417c7e2be9c9a7079eddf627ff52b90","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"667b6e52048eaf4dbcf1707ed87ffd44abb9cb38","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"4fdb0f162ccdbe9626863b10003855703253fa29","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"b28596baf87e25a078789f1c05817c8a3bf71257","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"34a71f5361fc3adb5b7138da78750b0d535a8252","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vmxnet3/vmxnet3_drv.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.2","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vmxnet3/vmxnet3_drv.c"]}],"references":["https://git.kernel.org/stable/c/2ddf51fcb6dd7d55ceef38e2e1a5ab2ab7fd47b0","https://git.kernel.org/stable/c/fbab6b73cc086e32698c86e43d1b16bf17d24c36","https://git.kernel.org/stable/c/28e382646417c7e2be9c9a7079eddf627ff52b90","https://git.kernel.org/stable/c/667b6e52048eaf4dbcf1707ed87ffd44abb9cb38","https://git.kernel.org/stable/c/28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8","https://git.kernel.org/stable/c/4fdb0f162ccdbe9626863b10003855703253fa29","https://git.kernel.org/stable/c/b28596baf87e25a078789f1c05817c8a3bf71257","https://git.kernel.org/stable/c/34a71f5361fc3adb5b7138da78750b0d535a8252"],"weaknesses":["CWE-20"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68299.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68299","state":"PUBLISHED","datePublished":"2026-08-10T12:02:33.213Z","dateUpdated":"2026-10-19T21:09:04.053Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.380Z"},"containers":{"cna":{"title":"vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"2ddf51fcb6dd7d55ceef38e2e1a5ab2ab7fd47b0","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"fbab6b73cc086e32698c86e43d1b16bf17d24c36","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"28e382646417c7e2be9c9a7079eddf627ff52b90","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"667b6e52048eaf4dbcf1707ed87ffd44abb9cb38","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"4fdb0f162ccdbe9626863b10003855703253fa29","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"b28596baf87e25a078789f1c05817c8a3bf71257","versionType":"git"},{"version":"45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc","status":"affected","lessThan":"34a71f5361fc3adb5b7138da78750b0d535a8252","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vmxnet3/vmxnet3_drv.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.2","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vmxnet3/vmxnet3_drv.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/2ddf51fcb6dd7d55ceef38e2e1a5ab2ab7fd47b0"},{"url":"https://git.kernel.org/stable/c/fbab6b73cc086e32698c86e43d1b16bf17d24c36"},{"url":"https://git.kernel.org/stable/c/28e382646417c7e2be9c9a7079eddf627ff52b90"},{"url":"https://git.kernel.org/stable/c/667b6e52048eaf4dbcf1707ed87ffd44abb9cb38"},{"url":"https://git.kernel.org/stable/c/28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8"},{"url":"https://git.kernel.org/stable/c/4fdb0f162ccdbe9626863b10003855703253fa29"},{"url":"https://git.kernel.org/stable/c/b28596baf87e25a078789f1c05817c8a3bf71257"},{"url":"https://git.kernel.org/stable/c/34a71f5361fc3adb5b7138da78750b0d535a8252"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The bug is triggered purely by a received Geneve-encapsulated packet processed in the vmxnet3 RX completion path (vmxnet3_rq_rx_complete -> vmxnet3_get_hdr_len); any remote host that can deliver such a frame to a VMware guest's vmxnet3 interface reaches the code, with no local access required.\nAC:L - The attacker only needs to send Geneve-encapsulated TCP traffic larger than the MTU to the target; the device then sets rcd.v4/v6/tcp from the inner header and the outer UDP protocol (or an outer/inner IP version mismatch) deterministically hits the BUG_ON, with no race or memory-layout dependency.\nPR:N - Packet reception and header-length estimation occur in the driver's NAPI RX path before any socket, credential, or authentication check, so an entirely unauthenticated remote sender triggers it.\nUI:N - The panic happens during normal NAPI RX processing of an incoming packet; no action by any local user or administrator is needed.\nS:U - The BUG_ON crashes the kernel that owns the vmxnet3 interface, and impact stays entirely within that kernel's security authority with no crossing into the hypervisor or another domain.\nC:N - The header parsing is bounded by the explicit skb_headlen()/maplen checks, so no out-of-bounds read occurs and no kernel memory contents are disclosed to the attacker before the BUG_ON aborts.\nI:N - No out-of-bounds or attacker-controlled write occurs; the mismatch is caught by the BUG_ON assertion, which halts execution rather than corrupting kernel memory or control flow.\nA:H - Hitting BUG_ON() in softirq/NAPI context oopses and panics the kernel, taking down the entire guest; a remote attacker can repeat it with a single crafted Geneve packet stream for a persistent denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:32:48.545Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-68299","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:46:52.382602Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","lang":"en","type":"CWE","description":"CWE-20 Improper Input Validation"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T21:09:04.053Z"}}]}}}