CVE-2026-68368
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: validate datagram bounds in ncm_unwrap_ntb() When unpacking host-supplied NTBs, ncm_unwrap_ntb() checks datagram length against frame_max but does not verify that the datagram fits within the declared block length. Additionally, when decoding multiple NTBs from a single socket buffer, subsequent block lengths are not checked against the actual remaining buffer data. With these checks missing, a malicious USB host can specify datagram offsets and lengths that point beyond the block, or supply secondary NTB headers declaring lengths larger than the buffer. skb_put_data() then copies adjacent kernel memory from skb_shared_info into the network skb. Fix this by verifying that sufficient buffer space remains for the NTB header before parsing, handling zero-length block declarations, ensuring that block lengths never exceed the remaining buffer space, and verifying that each datagram payload stays strictly within the block boundary.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-10 13:20:29.503000
Last modified
2026-11-06 17:19:31.043000
View original CVE JSON
{
"id": "CVE-2026-68368",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-08-10T13:20:29.503",
"lastModified": "2026-11-06T17:19:31.043",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_ncm: validate datagram bounds in ncm_unwrap_ntb()\n\nWhen unpacking host-supplied NTBs, ncm_unwrap_ntb() checks datagram length\nagainst frame_max but does not verify that the datagram fits within the\ndeclared block length. Additionally, when decoding multiple NTBs from a\nsingle socket buffer, subsequent block lengths are not checked against the\nactual remaining buffer data.\n\nWith these checks missing, a malicious USB host can specify datagram\noffsets and lengths that point beyond the block, or supply secondary NTB\nheaders declaring lengths larger than the buffer. skb_put_data() then\ncopies adjacent kernel memory from skb_shared_info into the network skb.\n\nFix this by verifying that sufficient buffer space remains for the NTB\nheader before parsing, handling zero-length block declarations, ensuring\nthat block lengths never exceed the remaining buffer space, and verifying\nthat each datagram payload stays strictly within the block boundary."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/usb/gadget/function/f_ncm.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
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"status": "affected"
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},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"drivers/usb/gadget/function/f_ncm.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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"status": "affected"
},
{
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"status": "unaffected"
},
{
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},
{
"version": "5.15.216",
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},
{
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"lessThanOrEqual": "6.1.*",
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},
{
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},
{
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"versionType": "original_commit_for_fix",
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}
]
}
]
}
],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-06T16:48:23.014514Z",
"id": "CVE-2026-68368",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
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