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NVD / CVE Program· CNA Linux

CVE-2026-43020: Bluetooth: MGMT: validate LTK enc_size on load

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 0f37d1e65c6d71ad94ccfb5c602163c525db789d, 257cdb960d8ff6d60bb6461b03c814b6cf0c9e64, 40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0f37d1e65c6d71ad94ccfb5c602163c525db789d, 257cdb960d8ff6d60bb6461b03c814b6cf0c9e64, 40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
May 1, 2026
Updated
Nov 6, 2026
EPSS
0.1% · 2th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-43020

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel3.4 and later · before 5.10.253
  • linux linux kernel5.11 and later · before 5.15.203
  • linux linux kernel5.16 and later · before 6.1.168
  • linux linux kernel6.2 and later · before 6.6.134
  • linux linux kernel6.7 and later · before 6.12.81
  • linux linux kernel6.13 and later · before 6.18.22
  • linux linux kernel6.19 and later · before 6.19.12
  • linux linux kernel7.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.4affected
    • 346af67b8d116f01ef696fd47959a55deb2db8b6 and later · before 0f37d1e65c6d71ad94ccfb5c602163c525db789daffected · git
    • 346af67b8d116f01ef696fd47959a55deb2db8b6 and later · before 257cdb960d8ff6d60bb6461b03c814b6cf0c9e64affected · git
    • 346af67b8d116f01ef696fd47959a55deb2db8b6 and later · before c34577f517b556fb6ca173d45bf7e766ae2564ceaffected · git
    • 346af67b8d116f01ef696fd47959a55deb2db8b6 and later · before f71695e81f4cb428f3c7e2138eae88199005b52caffected · git
    • 346af67b8d116f01ef696fd47959a55deb2db8b6 and later · before 82f342b3b006ca1d65f4890c05f2ec32fcb808b6affected · git
    • 346af67b8d116f01ef696fd47959a55deb2db8b6 and later · before 50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257affected · git
    • 346af67b8d116f01ef696fd47959a55deb2db8b6 and later · before 40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009affected · git
    • 346af67b8d116f01ef696fd47959a55deb2db8b6 and later · before b8dbe9648d69059cfe3a28917bfbf7e61efd7f15affected · git
    • before 3.4not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.18.1.el10_26.12.0-211.18.1.el10_2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-43018May 1, 2026 · Bluetooth: hci_event: fix potential UAF in hci_le_remote_conn_param_req_evt
    35Monitor
  • ← EarlierCVE-2026-43019May 1, 2026 · Bluetooth: hci_conn: fix potential UAF in set_cig_params_sync
    31Monitor
  • Later →CVE-2026-43021May 1, 2026 · Bluetooth: hci_sync: fix leaks when hci_cmd_sync_queue_once fails
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0f37d1e65c6d71ad94ccfb5c602163c525db789dVendor (CNA)
Linux Linux257cdb960d8ff6d60bb6461b03c814b6cf0c9e64Vendor (CNA)
Linux Linux40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009Vendor (CNA)
Linux Linux50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257Vendor (CNA)
Linux Linux82f342b3b006ca1d65f4890c05f2ec32fcb808b6Vendor (CNA)
Linux Linuxb8dbe9648d69059cfe3a28917bfbf7e61efd7f15Vendor (CNA)
Linux Linuxc34577f517b556fb6ca173d45bf7e766ae2564ceVendor (CNA)
Linux Linuxf71695e81f4cb428f3c7e2138eae88199005b52cVendor (CNA)
almalinux:kernel5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-687.12.1.el9_8 · AlmaLinux:9Package registry (OSV)
debian:linux6.1.170-1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-687.12.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-687.12.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-687.12.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-687.12.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-687.12.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-687.12.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-687.12.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-687.12.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-687.12.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)

+5

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records