GHSA-FC4H-XFF9-JP24
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33In the Linux kernel, the following vulnerability has been resolved:
usb: host: max3421: Fix shift-out-of-bounds in max3421_hub_control()
The max3421_hub_control() function handles USB hub class requests
to the virtual root hub. In the default branches of both the
ClearPortFeature and SetPortFeature switch statements, it modifies
max3421_hcd->port_status by left shifting 1 by the request's value
parameter. However, it does not validate whether this shift will exceed
the width of port_status.
So if a malicious userspace task with access to the root hub via
/dev/bus/usb/.../001 issues a USBDEVFS_CONTROL ioctl with wValue
greater than or equal to 32, the left shift operation invokes
shift-out-of-bounds undefined behavior. This results in arbitrary
bit corruption of port_status, including the normally-immutable
change bits, which can bypass internal state checks and confuse the
hub status.
Fix this by rejecting requests whose value exceeds the shift width
before performing the shift.
This issue was found using a KLEE-based symbolic execution tool for kernel drivers that I'm currently developing.
{
"affected": [],
"aliases": [
"CVE-2026-72483"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:22:22Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: host: max3421: Fix shift-out-of-bounds in max3421_hub_control()\n\nThe `max3421_hub_control()` function handles USB hub class requests\nto the virtual root hub. In the `default` branches of both the\n`ClearPortFeature` and `SetPortFeature` switch statements, it modifies\n`max3421_hcd-\u003eport_status` by left shifting 1 by the request\u0027s `value`\nparameter. However, it does not validate whether this shift will exceed\nthe width of `port_status`.\n\nSo if a malicious userspace task with access to the root hub via\n/dev/bus/usb/.../001 issues a USBDEVFS_CONTROL ioctl with `wValue`\ngreater than or equal to 32, the left shift operation invokes\nshift-out-of-bounds undefined behavior. This results in arbitrary\nbit corruption of `port_status`, including the normally-immutable\nchange bits, which can bypass internal state checks and confuse the\nhub status.\n\nFix this by rejecting requests whose `value` exceeds the shift width\nbefore performing the shift.\n\nThis issue was found using a KLEE-based symbolic execution tool for\nkernel drivers that I\u0027m currently developing.",
"id": "GHSA-fc4h-xff9-jp24",
"modified": "2026-08-17T06:33:32Z",
"published": "2026-08-15T06:32:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72483"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/00dd025324b56d39d37e57a08f473dab3a660f30"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/02d03c61e8a7b016956acb48e8a2512d16d87517"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/08b1d4cab0230697bc74c63fc4e40170a7559c54"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3be5f24e8270ba53b3c814d13689bb8644c86237"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4da073d57176d8e1c2bca34febfbc81d2560c1a5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cff06b03b530ae1fe8a13e93a7848f2130e00fb4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d512bdefd241b98f4d7bcb5bab5614a86411fad4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e5fa9d8f40746ec3447335c9642c03410f5fd3af"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.