{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72483", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.935Z", "datePublished": "2026-08-15T05:57:20.914Z", "dateUpdated": "2026-08-17T05:44:46.745Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:44:46.745Z" }, "descriptions": [ { "lang": "en", "value": "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->port_status` by left shifting 1 by the request's `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'm currently developing." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached when a local process issues USBDEVFS_CONTROL on the MAX3421 root hub (/dev/bus/usb/BBB/001); usb_submit_urb() routes ep0 control transfers through rh_call_control() to max3421_hub_control(), with no network or remote protocol path.\nAC:L - The attacker fully controls the hub-class wValue field in the ioctl and can reliably trigger the shift-out-of-bounds by sending SetPortFeature or ClearPortFeature with wValue>=32; no race, timing, or memory-layout conditions outside the attacker's control are required.\nPR:L - Only a basic unprivileged local account is needed: desktop, kiosk, and embedded MAX3421 deployments grant USB bus device-node access via udev uaccess/ACL or plugdev, and check_ctrlrecip() imposes no extra capability check for hub-class (USB_RECIP_OTHER) root-hub requests.\nUI:N - Exploitation is self-contained in the attacker's own process issuing the crafted USBDEVFS_CONTROL ioctl; no separate victim action, mount, or file open by another user is required.\nS:U - The undefined-behavior shift corrupts only the MAX3421 driver's port_status state inside kernel memory under the same security authority; it does not cross a VM, IOMMU, or sandbox boundary.\nC:H - Shift-out-of-bounds on port_status is kernel memory corruption of a security-relevant hub state word; corrupted status (including normally kernel-only change bits) is returned to userspace via GetPortStatus, enabling information disclosure from corrupted kernel state.\nI:H - The unchecked shift allows arbitrary bit manipulation of port_status, including normally immutable change bits, bypassing the USB_PORT_STAT_POWER gate that guards SetPortFeature updates and corrupting hub state that drives VBUS control and port reset logic.\nA:H - Shift-out-of-bounds is undefined behavior that can trap under UBSAN/KASAN or panic_on_warn, and corrupting port_status can confuse hub status polling, suspend/resume, and port-reset handling, causing USB host failure or kernel hang on embedded MAX3421 systems." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/usb/host/max3421-hcd.c" ], "versions": [ { "version": "2d53139f31626bad6f8983d8e519ddde2cbba921", "lessThan": "e5fa9d8f40746ec3447335c9642c03410f5fd3af", "status": "affected", "versionType": "git" }, { "version": "2d53139f31626bad6f8983d8e519ddde2cbba921", "lessThan": "08b1d4cab0230697bc74c63fc4e40170a7559c54", "status": "affected", "versionType": "git" }, { "version": "2d53139f31626bad6f8983d8e519ddde2cbba921", "lessThan": "3be5f24e8270ba53b3c814d13689bb8644c86237", "status": "affected", "versionType": "git" }, { "version": "2d53139f31626bad6f8983d8e519ddde2cbba921", "lessThan": "d512bdefd241b98f4d7bcb5bab5614a86411fad4", "status": "affected", "versionType": "git" }, { "version": "2d53139f31626bad6f8983d8e519ddde2cbba921", "lessThan": "00dd025324b56d39d37e57a08f473dab3a660f30", "status": "affected", "versionType": "git" }, { "version": "2d53139f31626bad6f8983d8e519ddde2cbba921", "lessThan": "02d03c61e8a7b016956acb48e8a2512d16d87517", "status": "affected", "versionType": "git" }, { "version": "2d53139f31626bad6f8983d8e519ddde2cbba921", "lessThan": "4da073d57176d8e1c2bca34febfbc81d2560c1a5", "status": "affected", "versionType": "git" }, { "version": "2d53139f31626bad6f8983d8e519ddde2cbba921", "lessThan": "cff06b03b530ae1fe8a13e93a7848f2130e00fb4", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/usb/host/max3421-hcd.c" ], "versions": [ { "version": "3.16", "status": "affected" }, { "version": "0", "lessThan": "3.16", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e5fa9d8f40746ec3447335c9642c03410f5fd3af" }, { "url": "https://git.kernel.org/stable/c/08b1d4cab0230697bc74c63fc4e40170a7559c54" }, { "url": "https://git.kernel.org/stable/c/3be5f24e8270ba53b3c814d13689bb8644c86237" }, { "url": "https://git.kernel.org/stable/c/d512bdefd241b98f4d7bcb5bab5614a86411fad4" }, { "url": "https://git.kernel.org/stable/c/00dd025324b56d39d37e57a08f473dab3a660f30" }, { "url": "https://git.kernel.org/stable/c/02d03c61e8a7b016956acb48e8a2512d16d87517" }, { "url": "https://git.kernel.org/stable/c/4da073d57176d8e1c2bca34febfbc81d2560c1a5" }, { "url": "https://git.kernel.org/stable/c/cff06b03b530ae1fe8a13e93a7848f2130e00fb4" } ], "title": "usb: host: max3421: Fix shift-out-of-bounds in max3421_hub_control()", "x_generator": { "engine": "bippy-1.2.0" } } } }