---
title: "CVE-2026-93121: Linux Kernel - Use After Free"
description: "Linux kernel contains a use-after-free vulnerability in usb gadget f_fs component caused by improper fence cleanup in ffs_dmabuf_transfer() error paths, letting attackers cause undefined behavior, exploit requires triggering specific error conditions."
url: https://panop.io/threat-heartbeat/CVE-2026-93121/
---

# CVE-2026-93121 Linux Kernel - Use After Free

Linux kernel contains a use-after-free vulnerability in usb gadget f\_fs component caused by improper fence cleanup in ffs\_dmabuf\_transfer() error paths, letting attackers cause undefined behavior, exploit requires triggering specific error conditions.

CVSS base score 7.0 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.15% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-93121)

## Details

Type

Use After Free

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Published

17 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for ffs\_dmabuf\_transfer() fence cleanup.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-93121](https://nvd.nist.gov/vuln/detail/CVE-2026-93121)
- [https://git.kernel.org/stable/c/58952c83dfe6ea3294a74734d2d1018c1120779a](https://git.kernel.org/stable/c/58952c83dfe6ea3294a74734d2d1018c1120779a)
- [https://git.kernel.org/stable/c/5fd8baacc7dc477df9cac61b45491840247a9b1e](https://git.kernel.org/stable/c/5fd8baacc7dc477df9cac61b45491840247a9b1e)
- [https://git.kernel.org/stable/c/621707dc67c9846fd876d7579ec951d92aa033f1](https://git.kernel.org/stable/c/621707dc67c9846fd876d7579ec951d92aa033f1)
- [https://git.kernel.org/stable/c/be539138d9a187af3b884525a395db10797c64f1](https://git.kernel.org/stable/c/be539138d9a187af3b884525a395db10797c64f1)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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