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Linux Kernel CVE-2026-53281

| EUVDEUVD-2026-39886 HIGH
NULL Pointer Dereference (CWE-476)
2026-06-26 Linux GHSA-p9cf-q2gf-35mq
8.8
CVSS 3.1 · Vendor: Linux
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Severity by source

Vendor (Linux) PRIMARY
8.8 HIGH
AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
vuln.today AI
5.8 MEDIUM

Local low-privileged trigger (AV:L/PR:L) of an explicitly unlikely race (AC:H); reliable impact is a kernel crash (A:H) with only conditional UAF-driven C/I exposure (C:L/I:L).

3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
4.0 AV:L/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/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
5.5 MEDIUM
qualitative

Primary rating from Vendor (Linux).

CVSS VectorVendor: Linux

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

Lifecycle Timeline

5
Analysis Generated
Jun 28, 2026 - 09:52 vuln.today
CVSS changed
Jun 28, 2026 - 08:22 NVD
8.8 (HIGH)
Patch available
Jun 26, 2026 - 21:02 EUVD
CVE Published
Jun 26, 2026 - 19:40 cve.org
HIGH 8.8
CVE Published
Jun 26, 2026 - 19:40 cve.org
UNKNOWN (no severity yet)

DescriptionCVE.org

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

iommu/vt-d: Avoid NULL pointer dereference or refcount corruption

Commit 60f030f7418d ("iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE") fixed a NULL pointer dereference in an unlikely situation partly.

If dev_pasid is not found in the dev_pasids list, it remains NULL. However, the teardown operations are executed unconditionally, this lead to a NULL pointer dereference or refcount corruption.

If the domain was never attached to this IOMMU, info will be NULL, which would cause an immediate dereference when checking --info->refcnt.

Even if info is not NULL, decrementing the refcount without having removed a valid PASID might unbalance the count. This could lead to premature dropping of the refcount to 0, potentially causing a use-after-free for the remaining active devices sharing the domain.

Fix it by returning early if dev_pasid is NULL, before executing the teardown operations.

Issue found by AI review and suggested by Kevin Tian. https://sashiko.dev/#/patchset/20260421031347.1408890-1-zhenzhong.duan%40intel.com

AnalysisAI

Local privilege escalation or denial of service in the Linux kernel's Intel VT-d IOMMU driver (iommu/vt-d) arises from incomplete handling of a missing dev_pasid entry during PASID teardown; an authenticated low-privileged actor able to drive IOMMU/PASID detach operations can trigger a NULL pointer dereference or unbalanced refcount that may decay into a use-after-free. This completes an earlier partial fix (commit 60f030f7418d) and is tagged as Denial of Service. There is no public exploit identified at time of analysis, and EPSS exploitation probability is low at 0.17% (6th percentile).

Technical ContextAI

The flaw lives in the kernel's Intel Virtualization Technology for Directed I/O (VT-d) IOMMU subsystem, which manages DMA remapping and PASID (Process Address Space ID) bindings between devices and IOMMU domains. During teardown, the code searches the dev_pasids list for a matching dev_pasid; if none is found it remains NULL, yet the teardown path previously executed unconditionally. When the domain was never attached to that IOMMU, the associated info pointer is NULL, so the info->refcnt check dereferences NULL; even when info is non-NULL, decrementing the refcount without having removed a valid PASID unbalances the count and can prematurely drop it to zero, producing a use-after-free for other active devices sharing the domain. The root-cause classes are CWE-476 (NULL Pointer Dereference) and CWE-416 (Use After Free), though the input lists CWE as N/A. CPE coverage is the generic cpe:2.3:a:linux:linux:*, i.e. the mainline/stable kernel rather than a specific distribution.

RemediationAI

Upstream fix available (stable commits), released patched version per stable tree metadata; apply your distribution's kernel update that incorporates commits 79ea2feb917b, 9022cb9ac0c2 or cdfe3c9f2c9e (git.kernel.org/stable/c/...), which add an early return when dev_pasid is NULL before any teardown operations. Track and apply the fixed stable releases (the 6.13.x/6.14, and later 6.18.x/7.0.x/7.1 series identified in EUVD) via your vendor's normal kernel package channel. There is no clean feature toggle that disables this code path without disabling IOMMU/PASID functionality, so the primary compensating control is restricting local access: limit which users and containers can perform device/PASID attach-detach operations and reduce exposure of untrusted local workloads on hosts using VT-d with SVA/PASID; the trade-off is that disabling Intel VT-d (intel_iommu=off) or scalable-mode PASID would remove DMA isolation and device-assignment/SVA capabilities, which is generally undesirable on virtualization hosts. Reference the NVD advisory https://nvd.nist.gov/vuln/detail/CVE-2026-53281 for canonical links.

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
Container suse/sl-micro/6.0/base-os-container:2.1.3-7.168 Container suse/sl-micro/6.1/base-os-container:2.2.1-5.149 Affected
Container suse/sl-micro/6.0/rt-os-container:2.1.3-7.197 Container suse/sl-micro/6.1/rt-os-container:2.2.1-5.145 Affected
Image SLES15-SP7-Azure-3P Image SLES15-SP7-Azure-Basic Image SLES15-SP7-Azure-Standard Image SLES15-SP7-HPC-Azure Affected
Image SLES15-SP7-BYOS-Azure Image SLES15-SP7-BYOS-GCE Image SLES15-SP7-CHOST-BYOS-Aliyun Image SLES15-SP7-CHOST-BYOS-Azure Image SLES15-SP7-CHOST-BYOS-EC2 Image SLES15-SP7-CHOST-BYOS-GCE Image SLES15-SP7-CHOST-BYOS-GDC Image SLES15-SP7-CHOST-BYOS-SAP-CCloud Image SLES15-SP7-EC2 Image SLES15-SP7-EC2-ECS-HVM Image SLES15-SP7-GCE Image SLES15-SP7-HPC-BYOS-Azure Image SLES15-SP7-HPC-BYOS-EC2 Image SLES15-SP7-HPC-BYOS-GCE Image SLES15-SP7-Hardened-BYOS-Azure Image SLES15-SP7-Hardened-BYOS-EC2 Image SLES15-SP7-Hardened-BYOS-GCE Image SLES15-SP7-SAPCAL-Azure Image SLES15-SP7-SAPCAL-EC2 Image SLES15-SP7-SAPCAL-GCE Affected
Image SLES15-SP7-SAP-Azure Image SLES15-SP7-SAP-Azure-3P Image SLES15-SP7-SAP-BYOS-Azure Image SLES15-SP7-SAP-BYOS-EC2 Image SLES15-SP7-SAP-BYOS-GCE Image SLES15-SP7-SAP-EC2 Image SLES15-SP7-SAP-GCE Image SLES15-SP7-SAP-Hardened-Azure Image SLES15-SP7-SAP-Hardened-BYOS-Azure Image SLES15-SP7-SAP-Hardened-BYOS-EC2 Image SLES15-SP7-SAP-Hardened-BYOS-GCE Image SLES15-SP7-SAP-Hardened-GCE Affected

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CVE-2026-53281 vulnerability details – vuln.today

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