CVE-2026-31779

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mvm: fix potential out-of-bounds read in iwl_mvm_nd_match_info_handler() The memcpy function assumes the dynamic array notif->matches is at least as large as the number of bytes to copy. Otherwise, results->matches may contain unwanted data. To guarantee safety, extend the validation in one of the checks to ensure sufficient packet length. Found by Linux Verification Center (linuxtesting.org) with SVACE.

CVSS Details

CVSS Score

8.1

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

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

Linux Kernel < v6.6 (特定commit之前)

Linux Kernel < v6.1 (特定commit之前)

Linux Kernel < v5.15 (特定commit之前)

PoC / Exploit Code

⚠ For Security Research Only

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

python

/*
 * Conceptual PoC for CVE-2026-31779
 * This snippet demonstrates the vulnerable logic in the kernel driver.
 */

#include <linux/kernel.h>
#include <linux/module.h>

// Vulnerable structure representation
struct iwl_mvm_nd_match_info_notif {
    __le16 length;
    u8 matches[]; // Dynamic array
};

void vulnerable_iwl_mvm_nd_match_info_handler(struct iwl_mvm_nd_match_info_notif *notif) {
    // Simulated buffer to copy into
    u8 results_matches[32]; 
    
    // Vulnerability: No check if notif->length is valid before memcpy
    // If notif->length is larger than the actual packet size, this crashes.
    // If notif is crafted to be small but length says big, OOB read occurs.
    memcpy(results_matches, notif->matches, notif->length); 
}

/*
 * Exploitation requires sending a malformed 802.11 frame to the target device
 * where the length field in the notification header exceeds the actual payload size.
 */

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-31779
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-31779
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-31779/
[4] VulDB https://vuldb.com/cve/CVE-2026-31779
[5] https://git.kernel.org/stable/c/744fabc338e87b95c4d1ff7c95bc8c0f834c6d99
[6] https://git.kernel.org/stable/c/ca0e9491b98ca4c5b44204b0b3dd8062a3b5fba2
[7] https://git.kernel.org/stable/c/dd90880eb5ec5442b37eb2b95688f4a63f4883e3
[8] https://git.kernel.org/stable/c/e67d8c626ace80b0fa2b48c8ec0a46b508c93442
[9] https://git.kernel.org/stable/c/f6abac936a0dfd31d6c3e49205ec0ee75a8f887f
[10] https://git.kernel.org/stable/c/ffbed27ba15ef80d1c622eeedbfef03e501ae134

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-31779", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-01T15:16:41.330", "lastModified": "2026-05-11T18:02:49.520", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: iwlwifi: mvm: fix potential out-of-bounds read in iwl_mvm_nd_match_info_handler()\n\nThe memcpy function assumes the dynamic array notif->matches is at least\nas large as the number of bytes to copy. Otherwise, results->matches may\ncontain unwanted data. To guarantee safety, extend the validation in one\nof the checks to ensure sufficient packet length.\n\nFound by Linux Verification Center (linuxtesting.org) with SVACE."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "baseScore": 8.1, "baseSeverity": "HIGH", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-125"}]}], "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/744fabc338e87b95c4d1ff7c95bc8c0f834c6d99", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ca0e9491b98ca4c5b44204b0b3dd8062a3b5fba2", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/dd90880eb5ec5442b37eb2b95688f4a63f4883e3", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/e67d8c626ace80b0fa2b48c8ec0a46b508c93442", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/f6abac936a0dfd31d6c3e49205ec0ee75a8f887f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ffbed27ba15ef80d1c622eeedbfef03e501ae134", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}