CVE-2026-68434 - Vulnerability Details

- serial: 8250_mid: Fix NULL function pointer dereference on DNV/ICX-D/SNR platforms

Description

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

serial: 8250_mid: Fix NULL function pointer dereference on DNV/ICX-D/SNR platforms

Commit b1b4efea05a5 ("serial: 8250_mid: Disable DMA for selected
platforms") replaced the dnv_board setup and exit callbacks with
PTR_IF(false, ...), which evaluates to NULL. However, the three call
sites in mid8250_probe() and mid8250_remove() unconditionally
dereference these function pointers without NULL checks, causing a NULL
pointer dereference (kernel oops) on any Denverton (DNV), Ice Lake Xeon
D (ICX-D/CDF), or Snowridge (SNR) platform.

Fix this by adding the missing NULL checks before calling the setup and
exit callbacks.

Published: 2026-08-12

Score: 5.5 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

A NULL function pointer dereference in the 8250_mid driver can trigger a kernel oops on DNV, Ice Lake Xeon D, and Snowridge platforms. This flaw arises because setup and exit callbacks are set to NULL and are later dereferenced without checks, causing a crash and potential denial of service. The weakness is a standard NULL pointer dereference (CWE‑476).

Affected Systems

All Linux kernel implementations that include the 8250_mid driver on Denverton (DNV), Ice Lake Xeon D (ICX‑D/CDF), or Snowridge (SNR) hardware, prior to the inclusion of commit b1b4efea05a5.

Risk and Exploitability

The EPSS score is <1%, indicating a very low exploitation probability. The CVSS score of 5.5 indicates a moderate severity. The flaw is not yet catalogued in the CISA KEV list, and no public exploit is known. Based on the description, it is inferred that a successful exploit would require local or privileged access to the system, as the failure occurs in kernel space. In practice, the risk profile is moderate–low, focusing primarily on denial of service when the driver is exercised.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`763d61ded752fbb3116efc951eff4363f237b7e0`	affected	< bdaa8871b53fe9b1730ef64dda2fcd662fd83339
`c7d190bb07bf4e3b217c69370e94d1b4c80a40ad`	affected	< f85a42fb90399dedcf81c146d09c07e4548b1e8c
`0b3ed3fa227ba778cabed96e7f8d84addb8bdf9c`	affected	< 4ea933a36a14bec19b71025cdd8407bafbd67ec1
`587afb06a5d1dc5092d3d9e9ac3ccf22094d50c6`	affected	< 1096397c31f6bffa95e77bdd18fbca085be83e10
`977855894bca4b87afa50d21e3f3e85a5a0e901f`	affected	< 600dcd548fb2b00a69f447684f52ba45d5a3540e
`1cd54e217c6e2cdb794a897b2f855e13ffcee586`	affected	< b2a3eeb57ba24f8a0e34a69d40adcc63e5b9ca56
`9690e8a342632344984af72bc56b7a1fba61e6cb`	affected	< 8cbad52ccfa6a7f089cfab34979bc6cc3bff25be
`b1b4efea05a56c0995e4702a86d6624b4fdff32f`	affected	< 7fb13fd7e9a59a37cd911efff83abe19e3ee029d

Linux

unaffected

Version	Status	Constraints
`5.10.261`	affected	< 5.10.266
`5.15.212`	affected	< 5.15.217
`6.1.178`	affected	< 6.1.183
`6.6.145`	affected	< 6.6.148
`6.12.96`	affected	< 6.12.101
`6.18.39`	affected	< 6.18.42
`7.1.4`	affected	< 7.1.6

No data.

Vendor Product Confidence Versions

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[587afb06a5d1dc5092d3d9e9ac3ccf22094d50c6,1096397c31f6bffa95e77bdd18fbca085be83e10)`	affected	code_commit	—
`[977855894bca4b87afa50d21e3f3e85a5a0e901f,600dcd548fb2b00a69f447684f52ba45d5a3540e)`	affected	code_commit	—
`[1cd54e217c6e2cdb794a897b2f855e13ffcee586,b2a3eeb57ba24f8a0e34a69d40adcc63e5b9ca56)`	affected	code_commit	—
`[9690e8a342632344984af72bc56b7a1fba61e6cb,8cbad52ccfa6a7f089cfab34979bc6cc3bff25be)`	affected	code_commit	—
`[b1b4efea05a56c0995e4702a86d6624b4fdff32f,7fb13fd7e9a59a37cd911efff83abe19e3ee029d)`	affected	code_commit	—
`[763d61ded752fbb3116efc951eff4363f237b7e0,*]`	affected	code_commit	—
`[c7d190bb07bf4e3b217c69370e94d1b4c80a40ad,*]`	affected	code_commit	—
`[0b3ed3fa227ba778cabed96e7f8d84addb8bdf9c,*]`	affected	code_commit	—
`[6.6.145,6.6.148)`	affected	semver	—
`[6.12.96,6.12.101)`	affected	semver	—
`[6.18.39,6.18.42)`	affected	semver	—
`[7.1.4,7.1.6)`	affected	semver	—
`[5.10.261,5.11)`	affected	semver	—
`[5.15.212,5.16)`	affected	semver	—
`[6.1.178,6.2)`	affected	semver	—

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`7.2-rc3`	affected	semver	—
`[0,7.2-rc3)`	unaffected	semver	—
`[6.6.148,6.7.0)`	unaffected	semver	—
`[6.12.101,6.13.0)`	unaffected	semver	—
`[6.18.42,6.19.0)`	unaffected	semver	—
`[7.1.6,7.2.0)`	unaffected	semver	—
`[0,*]`	unaffected	generic	—

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Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

Apply the kernel update that includes commit b1b4efea05a5.
Reboot the affected systems to load the updated 8250_mid driver.
If a kernel upgrade cannot be applied immediately, check the vendor’s kernel release notes or security advisories for the latest patches and follow general kernel maintenance best practices.

Generated by OpenCVE AI on August 13, 2026 at 14:00 UTC.

Tracking

Sign in to view the affected projects.

Advisories

Source	ID	Title
Debian DLA	DLA-4745-1	linux-6.12 security update

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00177.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/1096397c31f6bffa95e77bdd18fbca085be83e10
https://git.kernel.org/stable/c/4ea933a36a14bec19b71025cdd8407bafbd67ec1
https://git.kernel.org/stable/c/600dcd548fb2b00a69f447684f52ba45d5a3540e
https://git.kernel.org/stable/c/7fb13fd7e9a59a37cd911efff83abe19e3ee029d
https://git.kernel.org/stable/c/8cbad52ccfa6a7f089cfab34979bc6cc3bff25be
https://git.kernel.org/stable/c/b2a3eeb57ba24f8a0e34a69d40adcc63e5b9ca56
https://git.kernel.org/stable/c/bdaa8871b53fe9b1730ef64dda2fcd662fd83339
https://git.kernel.org/stable/c/f85a42fb90399dedcf81c146d09c07e4548b1e8c
https://lore.kernel.org/linux-cve-announce/2026081255-CVE-2026-68434-b1c1@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2026-68434
https://www.cve.org/CVERecord?id=CVE-2026-68434

History

Sun, 23 Aug 2026 13:15:00 +0000

Type	Values Removed	Values Added
References		https://git.kernel.org/stable/c/bdaa8871b53fe9b1730ef64dda2fcd662fd83339 https://git.kernel.org/stable/c/f85a42fb90399dedcf81c146d09c07e4548b1e8c

Wed, 19 Aug 2026 16:45:00 +0000

Type	Values Removed	Values Added
References		https://git.kernel.org/stable/c/4ea933a36a14bec19b71025cdd8407bafbd67ec1

Thu, 13 Aug 2026 12:15:00 +0000

Type	Values Removed	Values Added
References		https://lore.kernel.org/linux-cve-announce/2026081255-CVE-2026-68434-b1c1@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2026-68434 https://www.cve.org/CVERecord?id=CVE-2026-68434
Metrics	threat_severity `None`	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Low`

Wed, 12 Aug 2026 16:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-476

Wed, 12 Aug 2026 00:15:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: serial: 8250_mid: Fix NULL function pointer dereference on DNV/ICX-D/SNR platforms Commit b1b4efea05a5 ("serial: 8250_mid: Disable DMA for selected platforms") replaced the dnv_board setup and exit callbacks with PTR_IF(false, ...), which evaluates to NULL. However, the three call sites in mid8250_probe() and mid8250_remove() unconditionally dereference these function pointers without NULL checks, causing a NULL pointer dereference (kernel oops) on any Denverton (DNV), Ice Lake Xeon D (ICX-D/CDF), or Snowridge (SNR) platform. Fix this by adding the missing NULL checks before calling the setup and exit callbacks.
Title		serial: 8250_mid: Fix NULL function pointer dereference on DNV/ICX-D/SNR platforms
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/1096397c31f6bffa95e77bdd18fbca085be83e10 https://git.kernel.org/stable/c/600dcd548fb2b00a69f447684f52ba45d5a3540e https://git.kernel.org/stable/c/7fb13fd7e9a59a37cd911efff83abe19e3ee029d https://git.kernel.org/stable/c/8cbad52ccfa6a7f089cfab34979bc6cc3bff25be https://git.kernel.org/stable/c/b2a3eeb57ba24f8a0e34a69d40adcc63e5b9ca56

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-08-12T00:07:21.897Z

Updated: 2026-08-23T12:46:23.299Z

Reserved: 2026-07-30T09:28:09.393Z

Link: CVE-2026-68434

Vulnrichment

No data.

NVD

Status : Received

Published: 2026-08-12T00:17:43.520

Modified: 2026-08-23T13:16:36.980

Link: CVE-2026-68434

Redhat

Severity : Low

Publid Date: 2026-08-12T00:00:00Z

Links: CVE-2026-68434 - Bugzilla

OpenCVE Enrichment

Updated: 2026-08-13T14:15:05Z

Weaknesses

CWE-476
NULL Pointer Dereference

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Subscriptions

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