CVE intelligence

CVE-2026-90209

Vulnerability intelligence

Published Sep 17, 2026Sources checked Nov 3, 2026

N/ACVSS not listedScore unavailable

What this means

Review the available evidence

CVE-2026-90209. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

CISA KEVNot listedBased on the latest collected catalog

EPSS0.2%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-90209?

In the Linux kernel, the following vulnerability has been resolved:

s390/debug: Fix deadlock during unregister

Unregistering an s390dbf debug area while one of the associated debugfs files is being written to can cause a deadlock:

$ echo >.../vmur/level $ rmmod vmur =================================================== debugfs write debugfs_file_get() debug_unregister() mutex_lock(debug_mutex) debugfs_remove() wait for debugfs_file_put() debug_file_ops.write() debug_input() mutex_lock(debug_mutex) ==> DEADLOCK

Fix this by splitting debug_unregister() into an s390dbf and debugfs part, and running only the s390dbf part with debug_mutex locked.

Source: NVD