What’s Vulnerable › Vulnerabilities

CVE-2026-43134: Bluetooth: L2CAP: Fix missing key size check for L2CAP_LE_CONN_REQ

• Severity: high (CVSS 8.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-06 · updated 2026-10-19
• Weakness: CWE-326

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix missing key size check for L2CAP_LE_CONN_REQ This adds a check for encryption key size upon receiving L2CAP_LE_CONN_REQ which is required by L2CAP/LE/CFC/BV-15-C which expects L2CAP_CR_LE_BAD_KEY_SIZE.

Affected products

• Linux kernel: from 3.14 before 5.10.252; from 5.11 before 5.15.202; from 5.16 before 6.1.165; from 6.2 before 6.6.128; from 6.7 before 6.12.75; from 6.13 before 6.18.16 — fixed in 5.10.252, 5.15.202, 6.1.165, 6.12.75, 6.18.16, 6.19.6

How to fix

Upgrade to a fixed version: Linux kernel 5.10.252, 5.15.202, 6.1.165, 6.12.75. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/138d7eca445ef37a0333425d269ee59900ca1104
• https://git.kernel.org/stable/c/335071c0c3637064ec250481f589075db44fe4e6
• https://git.kernel.org/stable/c/481ea39b342c347b6ac029f3d418486280be4e45
• https://git.kernel.org/stable/c/8dd43f9a9323f9c01bc8246da8d81a4c783c9e97
• https://git.kernel.org/stable/c/9118601ff90b79e8df3c0c98f48ae00c1b02ecef
• https://git.kernel.org/stable/c/96581749c7c14fbec32c35728520867929600041
• https://git.kernel.org/stable/c/ec91078e132179b04e0c3906b599816c056ceaad
• https://git.kernel.org/stable/c/fa6ad76fa8623c0a50d529cd5726fa5d819a3be4

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