CVE Catalog

CVE-2026-98201

Low risk· EPSS 8%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.18%

8th percentile - higher than 8% of all known CVEs

Summary

In the Linux kernel, the Input module leaks kernel stack memory via incomplete copying of the ff_effect structure in the compat path input_ff_effect_from_user(). Only the compat-sized prefix is copied, leaving uninitialized bytes that can be disclosed to userspace via UI_BEGIN_FF_UPLOAD. The fix zeroes the structure before copying.

Risk Assessment

This can lead to disclosure of sensitive kernel memory, constituting a security breach. It requires local access and privileges to the force feedback interface.

Recommendation

Update the Linux kernel to a version with the fix. Restrict access to force feedback interfaces for untrusted users.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: Input: zero ff_effect before compat copy in input_ff_effect_from_user In the compat path input_ff_effect_from_user() aliases the caller's native struct ff_effect with the smaller struct ff_effect_compat and copies only the compat sized prefix: compat_effect = (struct ff_effect_compat *)effect; if (copy_from_user(compat_effect, buffer, sizeof(struct ff_effect_compat))) The tail of the native structure is never written. Callers pass an uninitialized on-stack object, for example evdev_do_ioctl() for EVIOCSFF, so those bytes keep their previous stack contents. input_ff_upload() then stores the full native structure in ff->effects[id], from where a uinput based force feedback daemon can read it back via UI_BEGIN_FF_UPLOAD, disclosing kernel stack memory to userspace. Zero the effect before the compat copy.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS