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Response snapshot Nov 6, 2026, 17:11 UTC

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VulnerabilityCVE-2026-43020

Linux kernel: Bluetooth: MGMT: validate LTK enc_size on load

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.

At a glance

Exploited
Not known
Severity
7.8 High (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-43020 (opens a new tab)

What happened

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.

Scores and how they were measured

CVSS base severity

7.8

Version 3.1As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-43020 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 6). Linux kernel: Bluetooth: MGMT: validate LTK enc_size on load (CVE-2026-43020). https://kevwire.com/record/CVE-2026-43020

MLA

"Linux kernel: Bluetooth: MGMT: validate LTK enc_size on load (CVE-2026-43020)." KEVWire, 6 Nov. 2026, kevwire.com/record/CVE-2026-43020.

Chicago

KEVWire. "Linux kernel: Bluetooth: MGMT: validate LTK enc_size on load (CVE-2026-43020)." Last modified November 6, 2026. https://kevwire.com/record/CVE-2026-43020.

Evidence summary (plain text)

Linux kernel: Bluetooth: MGMT: validate LTK enc_size on load (May 1, 2026).
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.
CVSS 7.8 (version 3.1; evidence as of Nov 6, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-43020).
Sources:
NVD CVE-2026-43020: https://nvd.nist.gov/vuln/detail/CVE-2026-43020
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-06T15:21:05.474Z&lastModEndDate=2026-11-06T16:50:56.468Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-06T14:41:02.636Z&lastModEndDate=2026-11-06T16:20:56.228Z&resultsPerPage=500&startIndex=0
Record ID: CVE-2026-43020.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 6, 2026, 16:50 UTC. Ingestion is not an independent editorial investigation.

NVD status: Analyzed. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

Record JSON

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Record details

Record detail