Vulnerability in Linux

CVE-2026-53252

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: fix memory leak in error path of hci_alloc_dev() Early failures in Bluetooth HCI UART configuration leak SRCU percpu memory. When device initialization fails before hci_register_dev() completes, the HCI_UNREGISTER flag is never set. As a result, when the device reference count reaches zero, bt_host_release() evaluates this flag as false and falls back to a direct kfree(hdev). Because hci_release_dev() is bypassed, the SRCU struct initialized early in hci_alloc_dev() is never cleaned up, resulting in a leak of percpu memory. Fix the leak by explicitly calling cleanup_srcu_struct() in the fallback (unregistered) branch of bt_host_release() before freeing the device.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.001 (2.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 2.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-53252: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

  • Linux — versions 90dee0a0ff84fac8accd5be98412b3819f667149, c56b177efce8b62798e4d96bdb9867106cb7c4a0, bc0819a25e04cd68ef3568cfa51b63118fea39a7
  • Linux Kernel — versions 5.15.209, 6.16, 7.1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-53252?
CVE-2026-53252 is a medium-severity vulnerability in Linux, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.5/10. Published 2026-06-25.
How severe is CVE-2026-53252?
Medium severity. CVSS v3 base score is 5.5 out of 10.