CVE-2026-84270 Gvfs: mtp: out-of-bounds read in do_read()

Description

A flaw was found in the MTP backend in gvfs. When reading a file from a mounted MTP device, do_read() in gvfsbackendmtp.c trusts the data length returned by the device without limiting it to the original size requested by the client. If a malicious MTP device responds with more bytes than requested, this unrestricted length is passed directly to memcpy(). This causes the operation to read memory outside the intended boundaries. This allows an attacker who plugs in a malicious MTP device to cause a segmentation fault when a file is read and crash the gvfsd-mtp process, resulting in a denial of service.

Exploitable with physical access to the machine, without an account and if a user takes an action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector

Physical

Attack complexity

Low

Privileges required

None

Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected products and versions