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CVE-2026-64122 Linux CVE debrief

CVE-2026-64122 is a use-after-free vulnerability in the Linux kernel's mlx5e_tx_reporter_timeout_recover function. The vulnerability occurs when the function accesses sq->netdev after mlx5e_safe_reopen_channels() has torn down and freed the channel. This can cause a KASAN splat, indicating a use-after-free error. Linux kernel users and administrators should be aware of this vulnerability and take steps to mitigate it by updating the kernel and applying the necessary patches.

Vendor
Linux
Product
Unknown
CVSS
CRITICAL 9.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-19
Original CVE updated
2026-08-13
Advisory published
2026-07-19
Advisory updated
2026-08-13

Who should care

Linux kernel users and administrators, as well as security teams and vulnerability management teams, should be aware of this vulnerability and take steps to mitigate it. They should review their system configurations, update the Linux kernel to the latest version, and apply the necessary patches to prevent exploitation.

Technical summary

The vulnerability is caused by a use-after-free error in the mlx5e_tx_reporter_timeout_recover function. The function accesses sq->netdev after mlx5e_safe_reopen_channels() has torn down and freed the channel. To fix this, the three sq->netdev references should be replaced with priv->netdev, which is safe because priv outlives channel teardown. This fix prevents the KASAN splat and ensures the stability of the Linux kernel.

Defensive priority

High

Recommended defensive actions

  • Update the Linux kernel to the latest version
  • Apply the patch to fix the use-after-free vulnerability
  • Monitor system logs for potential exploitation attempts
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability was reported by an unknown source and has been resolved by replacing sq->netdev with priv->netdev in the mlx5e_tx_reporter_timeout_recover function. Linux kernel users should verify their system configurations and check for any potential exploitation attempts. The fix involves updating the Linux kernel to the latest version and applying the patch to prevent use-after-free errors.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-64122 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-64122

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

  • CVE-2026-64122 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-64122

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

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/152295aa7dc2c5e046606f7dadc84fce41136446

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/1604a2d68414aa4cc34faac0b7faa9c14455e8d3

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/7d260c5d2d89eb2c8c528d54b576b3aae3e20231

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

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.