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PatchSiren cyber security CVE debrief

CVE-2026-43019 Linux CVE debrief

CVE-2026-43019 is a HIGH-severity vulnerability in the Linux kernel, specifically affecting the Bluetooth HCI connection handling. The vulnerability has a CVSS score of 7.8 and was published on May 1, 2026. It involves a potential Use-After-Free (UAF) issue in the `set_cig_params_sync` function, which can lead to concurrent deletion or modification of `hci_conn` objects. This vulnerability requires local access and can result in high impact on confidentiality, integrity, and availability.

Vendor
Linux
Product
Unknown
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-01
Original CVE updated
2026-06-19
Advisory published
2026-05-01
Advisory updated
2026-06-19

Who should care

System administrators and security teams responsible for Linux kernel-based systems, especially those using Bluetooth functionality, should be aware of this vulnerability. This includes organizations with Linux-based servers, desktops, and embedded systems that utilize Bluetooth connections.

Technical summary

The vulnerability exists in the Linux kernel's Bluetooth HCI connection handling, specifically in the `set_cig_params_sync` function. The issue arises from the lack of proper locking mechanisms, allowing for concurrent access and potential UAF attacks. The CVSS vector is AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, indicating a high severity level. The vulnerability affects various Linux kernel versions, including 6.4, 6.5, 6.6, 6.7, and 7.0 RC versions.

Defensive priority

High priority due to potential for local privilege escalation and high impact on confidentiality, integrity, and availability.

Recommended defensive actions

  • Inventory and review Linux kernel versions in use, focusing on Bluetooth-enabled systems.
  • Apply patches from Linux kernel stable branches (e.g., 66d432e9b45bae7881ffcdb12cd8fd0bf254ef02).
  • Implement compensating controls, such as restricting Bluetooth access and monitoring system calls.
  • Review and update Linux kernel configurations to disable unnecessary Bluetooth features.
  • Monitor system logs for suspicious Bluetooth-related activity.

Evidence notes

The vulnerability was published on May 1, 2026, and last modified on June 19, 2026. It affects Linux kernel versions 6.4, 6.5, 6.6, 6.7, and 7.0 RC versions. The CVE record and NVD detail pages provide comprehensive information about the vulnerability, including CVSS scores and affected versions.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-43019 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-43019

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-43019 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-43019

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/66d432e9b45bae7881ffcdb12cd8fd0bf254ef02

    416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/7502c1cf303b69f71d085f5ff7251b0e1b0f09df

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/7d568fede8eac91161a60b710aa920abe9b0fb9f

    416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/a2639a7f0f5bf7d73f337f8f077c19415c62ed2c

    416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/bad65b4b0a96139f023eadc28a33125963208449

    416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.