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Linux Kernel CVE-2026-43123

| EUVDEUVD-2026-27684 MEDIUM
NULL Pointer Dereference (CWE-476)
2026-05-06 Linux GHSA-7853-m2m9-5q4x
Denial Of Service Linux Null Pointer Dereference
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 access with low privileges required to reach fbcon subsystem; impact is purely a kernel panic with no data exposure or integrity change.

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 LOW
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

4
Analysis Generated
Jul 24, 2026 - 01:11 vuln.today
CVSS changed
May 12, 2026 - 21:22 NVD
5.5 (MEDIUM)
Patch available
May 06, 2026 - 13:02 EUVD
CVE Published
May 06, 2026 - 11:27 nvd
MEDIUM 5.5

DescriptionCVE.org

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

fbcon: check return value of con2fb_acquire_newinfo()

If fbcon_open() fails when called from con2fb_acquire_newinfo() then info->fbcon_par pointer remains NULL which is later dereferenced.

Add check for return value of the function con2fb_acquire_newinfo() to avoid it.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

AnalysisAI

NULL pointer dereference in the Linux kernel framebuffer console (fbcon) subsystem allows a local low-privilege user to crash the system. The function con2fb_acquire_newinfo() fails to check the return value of fbcon_open(); when fbcon_open() fails, info->fbcon_par remains NULL and is subsequently dereferenced, triggering a kernel panic. Patches are available across all active stable branches (5.15.x through 7.0), EPSS is 0.02% at the 7th percentile, and no confirmed active exploitation is recorded in CISA KEV.

Technical ContextAI

The vulnerable code resides in the Linux kernel's fbcon (framebuffer console) driver subsystem, specifically in the con2fb_acquire_newinfo() function. The root cause is CWE-476 (NULL Pointer Dereference): when fbcon_open() is called inside con2fb_acquire_newinfo() and returns an error, the info->fbcon_par pointer is never initialized and remains NULL. Subsequent code that unconditionally dereferences this pointer causes a kernel panic. The vulnerability was introduced by commit d1baa4ffa677bf6986c460fcfd4cdaf8bfe66f0e, traceable to Linux 2.6.23, and was discovered through static analysis by the Linux Verification Center (linuxtesting.org) using the SVACE tool. Affected product is identified by CPE cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*. The fbcon subsystem is relevant primarily on systems with physical framebuffer console support - desktops, workstations, embedded Linux, and KVM/virtual machine consoles - rather than headless servers.

RemediationAI

The primary remediation is upgrading to a patched Linux kernel stable release appropriate to the deployed branch: 5.15.203, 6.1.165, 6.6.128, 6.12.75, 6.18.16, 6.19.6, or 7.0. Upstream fix commits are available at https://git.kernel.org/stable/c/d3e535533767c85788529e626478718b7e95a59f and branch-specific equivalents referenced at https://git.kernel.org/stable/c/f57b61624c86ef8f87f6e6b7dd0755de03d90e89, https://git.kernel.org/stable/c/011a0502801c8536f64141a2b61362c14f456544, https://git.kernel.org/stable/c/11a93180a70bb3095a9bd80d113d9277e30d9959, https://git.kernel.org/stable/c/3b5a754ec86bc6064af9aca76eb191c2405e6b0c, https://git.kernel.org/stable/c/a785c4e2a999c2d51dfcf40d317cfb30cc735d2c, and https://git.kernel.org/stable/c/0b038c0be6827dd2dbb1ce4f8d92d97c80cbe9cc. Ubuntu users should apply the update via USN-8492-1. For systems where immediate kernel upgrade is not feasible, a compensating control is to disable the fbcon framebuffer console subsystem - for example, by booting with the kernel parameter 'fbcon=map:0' or blacklisting relevant framebuffer modules - though this trade-off eliminates graphical console support. On headless servers where fbcon is not loaded or active, no compensating action is required as the vulnerable code path is unreachable.

Same weakness CWE-476 – NULL Pointer Dereference

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Vendor StatusVendor

SUSE

Severity: Medium
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Fixed
SUSE Linux Enterprise Desktop 15 SP7 Fixed
SUSE Linux Enterprise High Availability Extension 15 SP7 Fixed
SUSE Linux Enterprise High Availability Extension 15 SP7 Fixed
SUSE Linux Enterprise High Performance Computing 15 SP7 Fixed

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CVE-2026-43123 vulnerability details – vuln.today
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