{"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"}}}}