Out-of-bounds Read in Linux

CVE-2026-43427

In the Linux kernel, the following vulnerability has been resolved: usb: class: cdc-wdm: fix reordering issue in read code path Quoting the bug report: Due to compiler optimization or CPU out-of-order execution, the desc->length update can be reordered before the memmove. If this happens, wdm_read() can see the new length and call copy_to_user() on uninitialized memory. This also violates LKMM data race rules [1]. Fix it by using WRITE_ONCE and memory barriers.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (6.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 6.3% 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-2026-43427: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000

Affected products

  • Linux — versions afba937e540c902c989cd516fd97ea0c8499bb27, 2.6.26, 0
  • Linux Kernel — versions 2.6.26, 7.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-43427?
CVE-2026-43427 is a high-severity vulnerability in Linux, classified under Out-of-bounds Read. CVSS score: 7.1/10. Published 2026-05-08.
How severe is CVE-2026-43427?
High severity. CVSS v3 base score is 7.1 out of 10.