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Linux Kernel EUVDEUVD-2026-48885

| CVE-2026-64341 HIGH
Use After Free (CWE-416)
2026-07-25 Linux GHSA-jfg4-c35c-vjq6
Linux Use After Free Memory Corruption
7.8
CVSS 3.1 · NVD
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Recon
    Gain local shell access (PR:L)
  2. Delivery
    Attach or emulate IO-Warrior USB device
  3. Exploit
    Open iowarrior device file node
  4. Install
    Trigger USB disconnect event concurrently with file close
  5. C2
    Win release()/disconnect() race
  6. Execute
    Use-after-free in mutex_unlock()
  7. Impact
    Kernel memory corruption
  8. Step 8
    Local privilege escalation to root

Vulnerability Assessment

Weakness
CWE
CWE-416
ASVS 5.0
V15 - Secure Coding and Architecture Memory lifecycle management
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

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Exploitation Conditions

Exploitation requires: (1) local authenticated access to the target Linux system (PR:L); (2) the iowarrior kernel module loaded - this occurs automatically when an IO-Warrior USB HID device is attached, but the driver must be present; (3) the ability to open the iowarrior device file, implying device-node read/write permissions for the user; (4) the ability to trigger or race a USB disconnect event concurrently with the file release() call, which typically requires physical access to the USB port or a USB relay/emulator, or a cooperating kernel thread. Systems without IO-Warrior hardware attached and with module autoloading restricted are not reachable. The race window between release() and disconnect() is narrow, making reliable exploitation timing-sensitive (AC:H in practice).
Impact

The provided CVSS 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) captures the local, low-privilege nature of the flaw correctly but rates AC:L, which understates the timing dependency inherent in a disconnect/release race condition. Real-world exploitation requires winning a narrow race window, pushing practical complexity higher than AC:L implies. EPSS at 0.21% (11th percentile) aligns with the race-dependent, driver-specific nature - this is not a trivially automated exploit. The vulnerability is not in CISA KEV and no POC is known. Despite C:H/I:H/A:H potential, the realistic exploitation barrier is significant: an attacker needs local code execution, physical or virtual USB device access or the ability to simulate a disconnect, and precise race timing. The primary realistic threat vector is a malicious local user on a multi-tenant Linux host with access to IO-Warrior USB devices, or a kernel security researcher. For most production environments without iowarrior hardware, the attack surface is not reachable without first loading the driver with a spoofed device.
Exploit ScenarioDerived

A local user on a shared Linux host with access to an IO-Warrior USB device opens the device file, then triggers or times a physical or emulated USB disconnect event to race with the release() call. If the race is won, mutex_unlock() accesses freed memory, producing a use-after-free condition that can be leveraged for kernel memory manipulation and local privilege escalation to root. No public POC exists at time of analysis.
This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.2% exploitation probability (EPSS)

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AnalysisAIv1 – Sep 03, 2026

Use-after-free in the Linux kernel USB iowarrior driver allows a local unprivileged user to corrupt kernel memory when a USB device disconnect races with a file release operation. The root cause is that mutex_unlock() is documented as non-atomic and may access the mutex structure after releasing the lock, meaning the driver data object can be freed while mutex_unlock() is still executing. An attacker who can trigger the race - by opening the iowarrior device and simultaneously provoking a USB disconnect - may achieve kernel memory corruption leading to privilege escalation. No public exploit code exists and EPSS is low (0.21%), but the impact class is standard kernel UAF.

RemediationAI

Update to a patched Linux kernel version: 7.2-rc3, 7.1.4, or 6.12.97 per stable channel. Apply the upstream fix commits from git.kernel.org/stable/c/3c0a7b29ebb391d5f50b115e86f842b709195b08, git.kernel.org/stable/c/71590982700fdeb39a37a500c877228b0140978e, or git.kernel.org/stable/c/c602254ba4c10f60a73cd99d147874f86a3f485c depending on the running branch. As a compensating control where patching is not immediately possible, blacklist the iowarrior kernel module (add 'blacklist iowarrior' to /etc/modprobe.d/) to prevent the driver from loading - note this disables all IO-Warrior USB devices. On systems where no IO-Warrior hardware is used, this workaround has no functional impact. Additionally, restrict physical USB port access and enforce kernel module loading policies (e.g., via module signing or lockdown mode) to reduce the attack surface.

Affected VersionsENISA

Linux patch: 0
Linux 946b960d13c15f050a3b848987aaca79f6a459b7 <c602254ba4c10f60a73cd99d147874f86a3f485c
Linux 946b960d13c15f050a3b848987aaca79f6a459b7 <71590982700fdeb39a37a500c877228b0140978e
Linux patch: 7.2-rc3
Linux patch: 7.1.4
Linux 2.6.21
Linux patch: 6.12.97
Linux 946b960d13c15f050a3b848987aaca79f6a459b7 <3c0a7b29ebb391d5f50b115e86f842b709195b08

Affected Packages

euvd linux no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

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Technical ContextAI · show details

The iowarrior driver (drivers/usb/misc/iowarrior.c) manages Code Mercenaries IO-Warrior USB HID devices in the Linux kernel. The vulnerability stems from CWE-416 (Use After Free): the driver allocated and freed its per-device private data structure under a mutex, but mutex_unlock() in the Linux locking subsystem is documented (see commit a51749ab34d9 and 2b9d9e0a9ba0) to potentially access the lock object after it is unlocked - making it unsafe to free the containing structure immediately before or after mutex_unlock(). When the USB subsystem calls disconnect() concurrently with a userspace process executing release(), both paths can operate on the same driver-data allocation, resulting in a use-after-free in the mutex_unlock() path. The fix replaces lifetime management with a kref (kernel reference count), ensuring the driver-data object is freed only after all references are dropped. Affected CPE: cpe:2.3:a:linux:linux:*.

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Severity by source

NVD PRIMARY 7.8 HIGH
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vuln.today AI 7.0 HIGH

Race condition requires precise disconnect/release timing, raising AC to H; all other metrics match the local, low-privilege driver exploit model.

3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
4.0 AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
SUSE 5.5 MEDIUM
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Red Hat 7.0 MEDIUM

Primary rating from NVD.

CVSS VectorNVD

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

4
CVSS changed
Sep 03, 2026 - 16:07 NVD
7.8 (HIGH)
Patch available
Jul 25, 2026 - 11:18 EUVD
CVE Published
Jul 25, 2026 - 08:50 cve.org
UNKNOWN (no severity yet)
CVE Published
Jul 25, 2026 - 08:50 nvd
HIGH 7.8

DescriptionNVD

In the Linux kernel, the following vulnerability has been resolved:

USB: iowarrior: fix use-after-free on disconnect race

mutex_unlock() may access the mutex structure after releasing the lock and therefore cannot be used to manage lifetime of objects directly (unlike spinlocks and refcounts). [1][2]

Use a kref to release the driver data to avoid use-after-free in mutex_unlock() when release() races with disconnect().

[1] a51749ab34d9 ("locking/mutex: Document that mutex_unlock() is non-atomic") [2] 2b9d9e0a9ba0 ("locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, can still use the lock object after it's unlocked")

Executive ViewAI

Why It Matters

The Linux kernel USB iowarrior driver contains a use-after-free vulnerability (CVSS 7.8) that allows unprivileged local users to corrupt kernel memory and escalate privileges to root. Any Linux system with multi-user access patterns and USB device support faces direct risk of unauthorized system compromise.

Business Impact: High
Compensating Controls

Apply vendor patch.

Threat Intelligence Overview

EPSS Score
0.2%
Top 89% exploitable
Prevalence
Ubiquitous
Linux kernel runs on the vast majority of servers and embedded systems
Data Quality
6 sources
Confidence: High
EUVD 🇯🇵JVN NVD CVE.org EPSS MSRC Vendor VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.2%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Small
Automatable· derived
No
Human Impact
High

Priority Score

39
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +39
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Use After Free HIGH

Use-after-free vulnerabilities occur when a program continues to access memory through a pointer after that memory has been deallocated.

Memory Corruption HIGH

Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.

Same weakness CWE-416 – Use After Free

View all
CVE-2019-0708 CRITICAL POC
9.8
CVE-2015-5119 CRITICAL POC
9.8
CVE-2014-0322 HIGH POC
8.8
CVE-2012-4792 HIGH POC
8.8
CVE-2009-4324 HIGH POC
7.8
CVE-2015-0313 CRITICAL POC
9.8
CVE-2015-5122 CRITICAL POC
9.8
CVE-2013-2551 HIGH POC
8.8

Same technique Use After Free

View all
CVE-2012-4969 HIGH POC
8.1

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
Container suse/sl-micro/6.0/base-os-container:2.1.3-7.208 Container suse/sl-micro/6.1/base-os-container:2.2.1-5.184 Affected
Container suse/sl-micro/6.0/kvm-os-container:2.1.3-6.218 Container suse/sl-micro/6.1/kvm-os-container:2.2.1-5.186 Affected
Container suse/sl-micro/6.0/rt-os-container:2.1.3-7.237 Container suse/sl-micro/6.1/rt-os-container:2.2.1-5.180 Affected
SUSE Linux Enterprise Real Time 15 SP7 SUSE Real Time Module 15 SP7 Fixed
SUSE Linux Micro 6.0 Fixed

References

Advisories & patches
ADVISORY https://nvd.nist.gov/vuln/detail/CVE-2026-64341 ADVISORY https://ubuntu.com/security/notices/USN-8726-1 ADVISORY https://ubuntu.com/security/notices/USN-8727-1 ADVISORY https://vuldb.com/vuln/383136 REF https://git.kernel.org/stable/c/30ec3025b771511625375fb3fb959aea3b45fb0d REF https://git.kernel.org/stable/c/3c0a7b29ebb391d5f50b115e86f842b709195b08 REF https://git.kernel.org/stable/c/4e7d3c98fed73d3be84d3e146d8d9be0309e725b REF https://git.kernel.org/stable/c/71590982700fdeb39a37a500c877228b0140978e REF https://git.kernel.org/stable/c/9472acd56a020c93be4189d2dba9c743b9fc8039 REF https://git.kernel.org/stable/c/c602254ba4c10f60a73cd99d147874f86a3f485c

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