Vulnerability in Linux

CVE-2025-21746

In the Linux kernel, the following vulnerability has been resolved: Input: synaptics - fix crash when enabling pass-through port When enabling a pass-through port an interrupt might come before psmouse driver binds to the pass-through port. However synaptics sub-driver tries to access psmouse instance presumably associated with the pass-through port to figure out if only 1 byte of response or entire protocol packet needs to be forwarded to the pass-through port and may crash if psmouse instance has not been attached to the port yet. Fix the crash by introducing open() and close() methods for the port and check if the port is open before trying to access psmouse instance. Because psmouse calls serio_open() only after attaching psmouse instance to serio port instance this prevents the potential crash.

Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)

EPSS: 0.001 (4.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21746?
CVE-2025-21746 is a medium-severity vulnerability in Linux, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 4.7/10. Published 2025-02-27.
How severe is CVE-2025-21746?
Medium severity. CVSS v3 base score is 4.7 out of 10.
Is CVE-2025-21746 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.