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Linux Kernel EUVDEUVD-2026-48628

| CVE-2026-64220 MEDIUM
Use of Uninitialized Resource (CWE-908)
2026-07-24 Linux GHSA-wjrp-p8qr-8jr3
5.5
CVSS 3.1 · NVD
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Severity by source

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

Local-only trigger requiring low privilege; no scope change, no confidentiality or integrity impact - sole effect is kernel crash causing high availability loss.

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

Primary rating from NVD.

CVSS VectorNVD

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

Lifecycle Timeline

5
Analysis Generated
Aug 11, 2026 - 22:53 vuln.today
CVSS changed
Aug 11, 2026 - 18:37 NVD
5.5 (MEDIUM)
Patch available
Jul 24, 2026 - 17:48 EUVD
CVE Published
Jul 24, 2026 - 15:23 cve.org
UNKNOWN (no severity yet)
CVE Published
Jul 24, 2026 - 15:23 nvd
MEDIUM 5.5

DescriptionNVD

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

device property: set fwnode->secondary to NULL in fwnode_init()

If a firmware node is allocated on the stack (for instance: temporary software node whose life-time we control) or on the heap - but using a non-zeroing allocation function - and initialized using fwnode_init(), its secondary pointer will contain uninitalized memory which likely will be neither NULL nor IS_ERR() and so may end up being dereferenced (for example: in dev_to_swnode()). Set fwnode->secondary to NULL on initialization.

AnalysisAI

Kernel denial-of-service in the Linux kernel's device property firmware node subsystem results from fwnode_init() failing to zero the secondary pointer before use, leaving it with uninitialized stack or heap garbage that may be incorrectly treated as a valid pointer and dereferenced in functions such as dev_to_swnode(). Local users with low privileges on any kernel version between the introducing commit and the respective stable patch releases can trigger a kernel panic, causing system downtime. No public exploit code exists and EPSS is 0.17% (7th percentile), reflecting negligible observed exploitation activity.

Technical ContextAI

The firmware node (fwnode) subsystem in the Linux kernel, implemented in drivers/base/property.c, provides an abstraction layer for device property sources including ACPI, Device Tree, and software-defined nodes. CWE-908 (Use of Uninitialized Resource) manifests because fwnode_init() did not assign NULL to fwnode->secondary prior to the fix. When a firmware node is allocated on the stack or via a non-zeroing heap allocator such as kmalloc without GFP_ZERO, the secondary field retains whatever bytes occupied that memory region. Code paths like dev_to_swnode() check whether secondary is non-NULL and non-IS_ERR() before dereferencing it; with uninitialized garbage in that field, this check passes spuriously, resulting in an invalid pointer dereference and kernel oops or BUG(). The fix is a one-line addition of 'fwnode->secondary = NULL' inside fwnode_init(). Affected CPE: cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*.

RemediationAI

Upgrade to a patched stable kernel: 5.15.209 or later (5.15.x LTS), 6.1.175 or later (6.1.x LTS), 6.6.142 or later (6.6.x LTS), 6.12.92 or later (6.12.x), 6.18.34 or later (6.18.x), 7.0.11 or later (7.0.x), or 7.1 and above for mainline. Upstream fix commits for all stable branches are indexed at https://git.kernel.org/stable/c/f59e686c778cb41b8f7aa8fab2afd6a01afb3d47 and the related commits listed in the references. Ubuntu users should apply packages from USN-8618-1 or USN-8620-1. If immediate kernel update is not feasible, restricting local user access using SELinux or AppArmor mandatory access control policies to prevent untrusted users from triggering the affected device-property subsystem code paths reduces exposure, though it does not eliminate the underlying defect and introduces policy management overhead.

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Micro 6.2 Fixed
openSUSE Leap 16.0 Fixed
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise Module for Basesystem 15 SP7 Affected
SUSE Linux Enterprise Server 15 SP7 Affected

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EUVD-2026-48628 vulnerability details – vuln.today

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