CVE-2026-43020

CVEs › CVE-2026-43020

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: validate LTK enc_size on load Load Long Term Keys stores the user-provided enc_size and later uses it to size fixed-size stack operations when replying to LE LTK requests. An enc_size larger than the 16-byte key buffer can therefore overflow the reply stack buffer. Reject oversized enc_size values while validating the management LTK record so invalid keys never reach the stored key state.

Overview

State: PUBLISHED
Assigner (CNA): Linux
CVSS severity: high
CVSS score: 7.8 / 10
CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Effective score: 7.8 / 10 HIGH source: CNA overview
CWE(s): —
Reserved: 2026-05-01
Published: 2026-05-01 16:15 UTC
Last updated: 2026-05-12 00:16 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/43xxx/CVE-2026-43020.json
Linked Threat: CVE-2026-43020 — CVE-2026-43020

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-05-01 15:16:46 UTC
NVD last modified: 2026-05-08 14:41:09 UTC
NVD CVSS v3.1: 7.8 / 10 HIGH source: nvd@nist.gov
NVD CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploitability subscore: 1.8 / 10
Impact subscore: 5.9 / 10
EPSS score: 0.0001 (probability of exploitation in next 30 days)
EPSS percentile: 2.55% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

NVD-assigned CWE(s): CWE-787 (differs from the CNA list above)

NVD / KEV / EPSS data refreshed 2026-05-25 09:13 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-26619
Assigner: Linux
Published: May 1, 2026, 2:15:23 PM
Updated: May 11, 2026, 10:16:09 PM
EUVD base score: 0.0 / 10
EUVD-reported EPSS: 0.0100
Vendors: Linux
Products: Linux (patch: 5.15.203)

Linux (346af67b8d116f01ef696fd47959a55deb2db8b6 <f71695e81f4cb428f3c7e2138eae88199005b52c)

Linux (patch: 7.0)

Linux (346af67b8d116f01ef696fd47959a55deb2db8b6 <b8dbe9648d69059cfe3a28917bfbf7e61efd7f15)

Linux (patch: 6.12.81)

Linux (346af67b8d116f01ef696fd47959a55deb2db8b6 <257cdb960d8ff6d60bb6461b03c814b6cf0c9e64)

Linux (patch: 6.19.12)

Linux (3.4)

Linux (patch: 0)

Linux (patch: 6.18.22)

Linux (346af67b8d116f01ef696fd47959a55deb2db8b6 <40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009)

Linux (patch: 6.6.134)

Linux (patch: 6.1.168)

Linux (patch: 5.10.253)

Linux (346af67b8d116f01ef696fd47959a55deb2db8b6 <50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257)

Linux (346af67b8d116f01ef696fd47959a55deb2db8b6 <0f37d1e65c6d71ad94ccfb5c602163c525db789d)

Linux (346af67b8d116f01ef696fd47959a55deb2db8b6 <c34577f517b556fb6ca173d45bf7e766ae2564ce)

Linux (346af67b8d116f01ef696fd47959a55deb2db8b6 <82f342b3b006ca1d65f4890c05f2ec32fcb808b6)

ENISA description: In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: validate LTK enc_size on load Load Long Term Keys stores the user-provided enc_size and later uses it to size fixed-size stack operations when replying to LE LTK requests. An enc_size larger than the 16-byte key buffer can therefore overflow the reply stack buffer. Reject oversized enc_size values while validating the management LTK record so invalid keys never reach the stored key state.

EUVD references (8)

Affected products (2)

Vendor	Product	Versions	Platforms
Linux	Linux	`346af67b8d116f01ef696fd47959a55deb2db8b6` (affected), `346af67b8d116f01ef696fd47959a55deb2db8b6` (affected), `346af67b8d116f01ef696fd47959a55deb2db8b6` (affected), `346af67b8d116f01ef696fd47959a55deb2db8b6` (affected), `346af67b8d116f01ef696fd47959a55deb2db8b6` (affected), `346af67b8d116f01ef696fd47959a55deb2db8b6` (affected), `346af67b8d116f01ef696fd47959a55deb2db8b6` (affected), `346af67b8d116f01ef696fd47959a55deb2db8b6` (affected)	—
Linux	Linux	`3.4` (affected), `0` (unaffected), `5.10.253` (unaffected), `5.15.203` (unaffected), `6.1.168` (unaffected), `6.6.134` (unaffected), `6.12.81` (unaffected), `6.18.22` (unaffected), `6.19.12` (unaffected), `7.0` (unaffected)	—

Affected products — CPE 2.3 (7) NVD

NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*

Vendor references (8)

References embedded in the original CVE record by the assigning CNA.

Web references (14)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

http://cwe.mitre.org/data/definitions/787.html rapid7:cwe.mitre.org
https://attackerkb.com/topics/CVE-2026-43020 rapid7:attackerkb.com
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-26619 rapid7:euvd.enisa.europa.eu
https://git.kernel.org/stable/c/0f37d1e65c6d71ad94ccfb5c602163c525db789d tenable:git.kernel.org
https://git.kernel.org/stable/c/257cdb960d8ff6d60bb6461b03c814b6cf0c9e64 tenable:git.kernel.org
https://git.kernel.org/stable/c/40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009 tenable:git.kernel.org
https://git.kernel.org/stable/c/50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257 tenable:git.kernel.org
https://git.kernel.org/stable/c/82f342b3b006ca1d65f4890c05f2ec32fcb808b6 tenable:git.kernel.org
https://git.kernel.org/stable/c/b8dbe9648d69059cfe3a28917bfbf7e61efd7f15 tenable:git.kernel.org
https://git.kernel.org/stable/c/c34577f517b556fb6ca173d45bf7e766ae2564ce tenable:git.kernel.org
https://git.kernel.org/stable/c/f71695e81f4cb428f3c7e2138eae88199005b52c tenable:git.kernel.org
https://nvd.nist.gov/vuln/detail/CVE-2026-43020 tenable:nvd.nist.gov
https://www.cve.org/CVERecord?id=CVE-2026-43020 tenable:www.cve.org
https://www.first.org/epss/ tenable:www.first.org

NVD-tagged references (8)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://git.kernel.org/stable/c/0f37d1e65c6d71ad94ccfb5c602163c525db789d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/257cdb960d8ff6d60bb6461b03c814b6cf0c9e64 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/82f342b3b006ca1d65f4890c05f2ec32fcb808b6 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/b8dbe9648d69059cfe3a28917bfbf7e61efd7f15 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/c34577f517b556fb6ca173d45bf7e766ae2564ce 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/f71695e81f4cb428f3c7e2138eae88199005b52c 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch

Remediations (16)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

CISA Warns of Exploited Microsoft Defender 0-Day Flaws

web:cyberpress.org

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .

2026-05-23 20:23 UTC
Microsoft Patch Tuesday April 2026 - 168 Vulnerabilities Fixed ...

web:cybersecuritynews.com

Microsoft has released its April 2026 Patch Tuesday security update, addressing 168 vulnerabilities across its product portfolio including one actively exploited zero-day and one publicly disclosed flaw that organizations must prioritize immediately.

2026-05-23 20:23 UTC
Patch Tuesday, May 2026 Edition - Krebs on Security

web:krebsonsecurity.com

Microsoft expects that exploitation is more likely. May's Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws.

2026-05-23 20:23 UTC
Security Update Guide - Microsoft

web:portal.msrc.microsoft.com

The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

2026-05-23 20:23 UTC
Critical Patches Issued for Microsoft Products, April 14, 2026

web:www.cisecurity.org

<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...

2026-05-23 20:23 UTC
May 2026 Patch Tuesday: Updates and Analysis | CrowdStrike

web:www.crowdstrike.com

Microsoft has released security updates for 130 vulnerabilities, including 30 critical, in its May 2026 Patch Tuesday rollout.

2026-05-23 20:23 UTC
Oracle Critical Patch Update Advisory - April 2026

web:www.oracle.com

This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.

2026-05-23 20:23 UTC
CVE 2026 — The Vulnerabilities That Matter Most Right Now

web:www.penligent.ai

Second, chipset and OEM dependencies make remediation slower and messier than software-only patching. Google's bulletin explains the two Android patch levels for March 2026 and clarifies that devices with security patch levels of 2026 -03-01 or 2026 -03-05 are protected against the associated issues, depending on applicable components.

2026-05-23 20:23 UTC
April 2026 Third-Party Vulnerabilities and Patches | Recast

web:www.recastsoftware.com

This April was the most active month observed so far in terms of third‑party vulnerability disclosures and remediation activity. During the month, 360 unique vulnerabilities were identified across 96 applications, with vendors releasing 172 patched versions to address these issues. Compared to earlier months, April represents a clear peak in both vulnerability volume and patch output ...

2026-05-23 20:23 UTC
Patch Tuesday May 2026: Security Updates & CVE Analysis

web:zecurit.com

Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

2026-05-23 20:23 UTC
THREAT ADVISORY RedSun Zero-Day (Windows Defender) April 17, 2026

web:blackswan-cybersecurity.com

Cloud Files API activity originating outside legitimate OneDrive/sync processes. Mitigation Steps: Apply all Windows updates immediately (monitor MSRC for an emergency RedSun-specific patch . None released as of April 17, 2026 ). Supplement Defender with a secondary EDR solution (e.g., Huntress) capable of detecting Defender bypasses.

2026-05-26 02:45 UTC
Microsoft and Adobe Patch Tuesday, April 2026 Security Update Review

web:blog.qualys.com

With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.

2026-05-26 02:45 UTC
Security Advisory Bulletin 064 | Ubiquiti Community

web:community.ui.com

Published: May 21, 2026 Updated: May 22, 2026 Version: 1.1 Revision: 1.1 Summary 1 of 5 A malicious actor with access to the network and high privileges could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection. Affected Products: UniFi OS Server (Version 5.0.6 and earlier) Mitigation : Update your UniFi OS Server to Version 5.0.8 or later ...

2026-05-26 02:45 UTC
Patch Tuesday, April 2026 Edition - Krebs on Security

web:krebsonsecurity.com

For a clickable, per- patch breakdown, check out the SANS Internet Storm Center Patch Tuesday roundup. Running into problems applying any of these updates?

2026-05-26 02:45 UTC
Security Update Guide - Microsoft

web:msrc.microsoft.com

The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.

2026-05-26 02:45 UTC
April 2026 Patch Tuesday: Updates and Analysis | CrowdStrike

web:www.crowdstrike.com

Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.

2026-05-26 02:45 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-43020.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/mgmt.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0f37d1e65c6d71ad94ccfb5c602163c525db789d",
              "status": "affected",
              "version": "346af67b8d116f01ef696fd47959a55deb2db8b6",
              "versionType": "git"
            },
            {
              "lessThan": "257cdb960d8ff6d60bb6461b03c814b6cf0c9e64",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "c34577f517b556fb6ca173d45bf7e766ae2564ce",
              "status": "affected",
              "version": "346af67b8d116f01ef696fd47959a55deb2db8b6",
              "versionType": "git"
            },
            {
              "lessThan": "f71695e81f4cb428f3c7e2138eae88199005b52c",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "82f342b3b006ca1d65f4890c05f2ec32fcb808b6",
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            },
            {
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            },
            {
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            },
            {
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            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/mgmt.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.4"
            },
            {
              "lessThan": "3.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.253",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.203",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.168",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.134",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.81",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.22",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.253",
                  "versionStartIncluding": "3.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.203",
                  "versionStartIncluding": "3.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
                },
                {
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.81",
                  "versionStartIncluding": "3.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.22",
                  "versionStartIncluding": "3.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.12",
                  "versionStartIncluding": "3.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "3.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: MGMT: validate LTK enc_size on load\n\nLoad Long Term Keys stores the user-provided enc_size and later uses\nit to size fixed-size stack operations when replying to LE LTK\nrequests. An enc_size larger than the 16-byte key buffer can therefore\noverflow the reply stack buffer.\n\nReject oversized enc_size values while validating the management LTK\nrecord so invalid keys never reach the stored key state."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T22:16:09.294Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/0f37d1e65c6d71ad94ccfb5c602163c525db789d"
        },
        {
          "url": "https://git.kernel.org/stable/c/257cdb960d8ff6d60bb6461b03c814b6cf0c9e64"
        },
        {
          "url": "https://git.kernel.org/stable/c/c34577f517b556fb6ca173d45bf7e766ae2564ce"
        },
        {
          "url": "https://git.kernel.org/stable/c/f71695e81f4cb428f3c7e2138eae88199005b52c"
        },
        {
          "url": "https://git.kernel.org/stable/c/82f342b3b006ca1d65f4890c05f2ec32fcb808b6"
        },
        {
          "url": "https://git.kernel.org/stable/c/50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257"
        },
        {
          "url": "https://git.kernel.org/stable/c/40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009"
        },
        {
          "url": "https://git.kernel.org/stable/c/b8dbe9648d69059cfe3a28917bfbf7e61efd7f15"
        }
      ],
      "title": "Bluetooth: MGMT: validate LTK enc_size on load",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43020",
    "datePublished": "2026-05-01T14:15:23.699Z",
    "dateReserved": "2026-05-01T14:12:55.975Z",
    "dateUpdated": "2026-05-11T22:16:09.294Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}