CVE-2026-64376
MediumIn the Linux kernel, the following vulnerability has been resolved: firmware_loader: fix device reference leak in firmware_upload_register() firmware_upload_register() -> fw_create_instance() -> device_initialize() After fw_create_instance() succeeds, the lifetime of the embedded struct device is expected to be managed through the device core reference counting, since fw_create_instance() has already called device_initialize(). In firmware_upload_register(), if alloc_lookup_fw_priv() fails after fw_create_instance() succeeds, the code reaches free_fw_sysfs and frees fw_sysfs directly instead of releasing the device reference with put_device(). This may leave the reference count of the embedded struct device unbalanced, resulting in a refcount leak. The issue was identified by a static analysis tool I developed and confirmed by manual review. Fix this by using put_device(fw_dev) in the failure path and letting fw_dev_release() handle the final cleanup, instead of freeing the instance directly from the error path.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected versions
Linux kernel versions
5.19
and later are affected. Fixed in
6.1.178,
6.6.145,
6.12.96,
6.18.39,
7.1.4,
7.2
and their respective stable series.
References
6 total-
Patch
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Frequently asked questions
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What is CVE-2026-64376?
CVE-2026-64376 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.19 onward and has been patched in 6.1.178, 6.6.145, 6.12.96 and others. CVE-2026-64376 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-64376?
CVE-2026-64376 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2026-64376?
Yes. CVE-2026-64376 has been patched. Fixed versions include 6.1.178, 6.6.145, 6.12.96 and others. If you are running Linux kernel 5.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-64376 actively exploited?
No. CVE-2026-64376 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.