CVE-2026-68299 (GCVE-0-2026-68299)
Vulnerability from cvelistv5
Published
2026-08-10 12:02
Modified
2026-08-19 16:32
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets
vmxnet3_get_hdr_len() assumes gdesc->rcd.v4/v6/tcp always describe the
outer header, but for a Geneve-encapsulated packet the device can set
them based on the inner header instead, signalled by the
VMXNET3_RCD_HDR_INNER_SHIFT bit in the completion descriptor. Since the
function never skips the outer encapsulation, this mismatch triggers:
- BUG_ON(hdr.ipv4->protocol != IPPROTO_TCP), because the outer
protocol is UDP (Geneve), not TCP.
- BUG_ON(hdr.eth->h_proto != ...), when the tunnel's outer and inner
IP versions differ (e.g. outer IPv6/inner IPv4 or vice versa).
Check VMXNET3_RCD_HDR_INNER_SHIFT up front and bail out, since the
function cannot locate the inner header it would need to parse. Also
convert the remaining BUG_ON()s in this function to return 0
defensively.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc Version: 45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc Version: 45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc Version: 45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc Version: 45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc Version: 45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc Version: 45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc Version: 45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/net/vmxnet3/vmxnet3_drv.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "2ddf51fcb6dd7d55ceef38e2e1a5ab2ab7fd47b0",
"status": "affected",
"version": "45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc",
"versionType": "git"
},
{
"lessThan": "fbab6b73cc086e32698c86e43d1b16bf17d24c36",
"status": "affected",
"version": "45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc",
"versionType": "git"
},
{
"lessThan": "28e382646417c7e2be9c9a7079eddf627ff52b90",
"status": "affected",
"version": "45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc",
"versionType": "git"
},
{
"lessThan": "667b6e52048eaf4dbcf1707ed87ffd44abb9cb38",
"status": "affected",
"version": "45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc",
"versionType": "git"
},
{
"lessThan": "28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8",
"status": "affected",
"version": "45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc",
"versionType": "git"
},
{
"lessThan": "4fdb0f162ccdbe9626863b10003855703253fa29",
"status": "affected",
"version": "45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc",
"versionType": "git"
},
{
"lessThan": "b28596baf87e25a078789f1c05817c8a3bf71257",
"status": "affected",
"version": "45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc",
"versionType": "git"
},
{
"lessThan": "34a71f5361fc3adb5b7138da78750b0d535a8252",
"status": "affected",
"version": "45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/net/vmxnet3/vmxnet3_drv.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.2"
},
{
"lessThan": "4.2",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.148",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.101",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.265",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.216",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.183",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.148",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.101",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.42",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.6",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "4.2",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"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-\u003ercd.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-\u003eprotocol != IPPROTO_TCP), because the outer\n protocol is UDP (Geneve), not TCP.\n- BUG_ON(hdr.eth-\u003eh_proto != ...), when the tunnel\u0027s 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."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.5,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"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 -\u003e vmxnet3_get_hdr_len); any remote host that can deliver such a frame to a VMware guest\u0027s 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\u0027s 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\u0027s 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": {
"dateUpdated": "2026-08-19T16:32:48.545Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"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"
}
],
"title": "vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-68299",
"datePublished": "2026-08-10T12:02:33.213Z",
"dateReserved": "2026-07-30T09:28:09.380Z",
"dateUpdated": "2026-08-19T16:32:48.545Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…