CVE-2026-43251

Description

In the Linux kernel, the following vulnerability has been resolved: HID: prodikeys: Check presence of pm->input_ep82 Fake USB devices can send their own report descriptors for which the input_mapping() hook does not get called. In this case, pm->input_ep82 stays NULL, which leads to a crash later. This does not happen with the real device, but can be provoked by imposing as one.

CVSS Details

CVSS Score

5.5

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Configurations (Affected Products)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE

Linux Kernel < 6.1 (根据Git commit推测)

Linux Kernel < 5.15 (根据Git commit推测)

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# Conceptual PoC using Python and pyusb (Simulation)
import usb.core
import usb.util

def trigger_crash():
    # Find the device (Mocking the attack)
    dev = usb.core.find(idVendor=0x1234, idProduct=0x5678)
    
    if dev is None:
        print("Device not found")
        return

    # Detach kernel driver if active
    for cfg in dev:
        for intf in cfg:
            if dev.is_kernel_driver_active(intf.bInterfaceNumber):
                dev.detach_kernel_driver(intf.bInterfaceNumber)
    
    # Set configuration
    dev.set_configuration()
    
    # Send a malicious report descriptor that bypasses input_mapping
    # This descriptor is crafted to avoid setting up pm->input_ep82
    malicious_descriptor = b'\x05\x01\x09\x06\xa1\x01\x05\x07\x19\xe0\x29\xe7\x15\x00\x25\x01\x75\x01\x95\x08\x81\x02\x95\x01\x75\x08\x81\x03\x95\x05\x75\x01\x05\x08\x19\x01\x29\x05\x91\x02\x95\x01\x75\x03\x91\x03\x95\x06\x75\x08\x15\x00\x25\x65\x05\x07\x19\x00\x29\x65\x81\x00\xc0'
    
    # Since we can't directly send a descriptor via pyusb easily to change HID parsing logic 
    # without a custom gadget driver, this represents the payload structure 
    # that would be sent by a malicious USB device.
    
    print("Sending malicious descriptor structure...")
    # In a real exploit, this hardware would present the bad descriptor on enumeration.

if __name__ == "__main__":
    trigger_crash()

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-43251
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-43251
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-43251/
[4] VulDB https://vuldb.com/cve/CVE-2026-43251
[5] https://git.kernel.org/stable/c/3f1b21cc67a15d7d081378a9b8747dd000a017b8
[6] https://git.kernel.org/stable/c/cee8337e1bad168136aecfe6416ecd7d3aa7529a
[7] https://git.kernel.org/stable/c/d08f35f843881ec504d7537a9bb728a073db3366
[8] https://git.kernel.org/stable/c/d5512ce892f774d37c53082adadfcad04f21b50e
[9] https://git.kernel.org/stable/c/e7ac1cd823cd2e9fcbd5cb0b261d6d35dbb79341
[10] https://git.kernel.org/stable/c/edccbf7d6dc05d692bde3a89de5a4001f72a0fa4
[11] https://git.kernel.org/stable/c/ee572578f09f0e743e9383393a75c3a7a0f9b4c2
[12] https://git.kernel.org/stable/c/f580c79683356632f12f2c2029f2fe936d953aa1

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-43251", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:45.740", "lastModified": "2026-05-11T18:51:22.587", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nHID: prodikeys: Check presence of pm->input_ep82\n\nFake USB devices can send their own report descriptors for which the\ninput_mapping() hook does not get called. In this case, pm->input_ep82 stays\nNULL, which leads to a crash later.\n\nThis does not happen with the real device, but can be provoked by imposing as\none."}], "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": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "5.10.252", "matchCriteriaId": "D6E3A666-FDAF-4C4C-AFEE-803E15871F9A"}, {"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"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/3f1b21cc67a15d7d081378a9b8747dd000a017b8", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/cee8337e1bad168136aecfe6416ecd7d3aa7529a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d08f35f843881ec504d7537a9bb728a073db3366", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d5512ce892f774d37c53082adadfcad04f21b50e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/e7ac1cd823cd2e9fcbd5cb0b261d6d35dbb79341", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/edccbf7d6dc05d692bde3a89de5a4001f72a0fa4", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ee572578f09f0e743e9383393a75c3a7a0f9b4c2", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/f580c79683356632f12f2c2029f2fe936d953aa1", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}