# CVE-2026-84270: GNOME gvfs buffer overflow in MTP backend

Source: https://junglewise.ai/threats/cve-2026-84270-gnome-gvfs-buffer-overflow-in-mtp-backend  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-01. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-84270 · Severity: medium · CVSS 4.3 · Published 2026-09-01

GNOME gvfs is a virtual filesystem implementation used to mount and access remote storage devices. A malicious MTP device can trick the gvfs MTP backend into reading more data than requested from memory, causing the gvfsd-mtp process to crash and making the device inaccessible to users until the service is restarted.

Technologies: [Gnome Gvfs](https://junglewise.ai/threats/technologies/gvfs). Vendors: [Gnome](https://junglewise.ai/threats/vendors/gnome).

## Quick answers

**Is CVE-2026-84270 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-84270 being exploited in the wild.

**How severe is CVE-2026-84270?** Medium severity, with a CVSS score of 4.3, published 1 September 2026.

**Which products and versions are affected?** Gnome Gvfs <UNKNOWN>.

**Is there a fix for CVE-2026-84270?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-84270 attacked?** It is attacked with physical access, in a software library.

**Am I affected by CVE-2026-84270?** Check whether you run Gnome Gvfs at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a buffer overflow in the MTP backend's do_read() function in gvfsbackendmtp.c. The root cause is that the code trusts the data length returned by an MTP device without validating it against the original request size. When a malicious MTP device responds with more bytes than requested, this unchecked length is passed directly to memcpy(), causing an out-of-bounds read that crashes the gvfsd-mtp daemon. The attack requires physical access to connect a malicious MTP device; no authentication or network access is required. An attacker can achieve denial of service by triggering a segmentation fault when any file is read from the compromised device.

## Affected products

- GNOME gvfs <UNKNOWN>

## Timeline

- 2026-09-01: disclosed

## References

- [https://gitlab.gnome.org/GNOME/gvfs](https://gitlab.gnome.org/GNOME/gvfs)
- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)

## Related threats

- [GNOME gvfs privilege escalation via symlink TOCTOU in admin daemon](https://junglewise.ai/threats/cve-2026-88924-gnome-gvfs-privilege-escalation-via-symlink-toctou-in-admin)
- [GNOME gvfs AFP backend heap buffer overflow](https://junglewise.ai/threats/cve-2026-84269-gnome-gvfs-afp-backend-heap-buffer-overflow)
- [GNOME gvfs SFTP backend heap overflow](https://junglewise.ai/threats/cve-2026-84268-gnome-gvfs-sftp-backend-heap-overflow)
- [GNOME gvfs SFTP buffer read vulnerability](https://junglewise.ai/threats/cve-2026-84267-gnome-gvfs-sftp-buffer-read-vulnerability)