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Vulnerability record · CVE-2026-43020 · published 1 May 2026

CVE-2026-43020: Linux kernel out-of-bounds write vulnerability

Linux · Linux Kernel

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.

7.8 CVSS 3.1 High EPSS 0.18% · top 93.7% CWE-787 · Out-of-bounds write
7.8CVSS 3.1 base score
0.18%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
8References
17 Jun 2026Last modified by NVD

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://git.kernel.org/stable/c/0f37d1e65c6d71ad94ccfb5c602163c525db789d Patch
https://git.kernel.org/stable/c/257cdb960d8ff6d60bb6461b03c814b6cf0c9e64 Patch
https://git.kernel.org/stable/c/40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009 Patch
https://git.kernel.org/stable/c/50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257 Patch
https://git.kernel.org/stable/c/82f342b3b006ca1d65f4890c05f2ec32fcb808b6 Patch
https://git.kernel.org/stable/c/b8dbe9648d69059cfe3a28917bfbf7e61efd7f15 Patch
https://git.kernel.org/stable/c/c34577f517b556fb6ca173d45bf7e766ae2564ce Patch
https://git.kernel.org/stable/c/f71695e81f4cb428f3c7e2138eae88199005b52c Patch

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Source: NIST National Vulnerability Database (record CVE-2026-43020), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.