Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2 char ac_ioctl null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2. This affects the function ac_ioctl of the component char. This manipulation causes null pointer dereference. This vulnerability is registered as CVE-2025-68797. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2 and classified as critical. Affected by this vulnerability is the function ac_ioctl of the component char. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: char: applicom: fix NULL pointer dereference in ac_ioctl Discovered by Atuin - Automated Vulnerability Discovery Engine. In ac_ioctl, the validation of IndexCard and the check for a valid RamIO pointer are skipped when cmd is 6. However, the function unconditionally executes readb(apbs[IndexCard].RamIO + VERS) at the end. If cmd is 6, IndexCard may reference a board that does not exist (where RamIO is NULL), leading to a NULL pointer dereference. Fix this by skipping the readb access when cmd is 6, as this command is a global information query and does not target a specific board context.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2025-68797 since 12/24/2025. The exploitation appears to be easy. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 298659 (Debian dla-4476 : linux-config-6.1 - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.160, 6.6.120, 6.12.64, 6.18.3 or 6.19-rc1 eliminates this vulnerability. Applying the patch 0b8b353e09888bccee405e0dd6feafb60360f478/d285517429a75423789e6408653e57b6fdfc8e54/74883565c621eec6cd2e35fe6d27454cf2810c23/f83e3e9f89181b42f6076a115d767a7552c4a39e/82d12088c297fa1cef670e1718b3d24f414c23f7 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (298659) and CERT Bund (WID-SEC-2026-0086). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel

Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 298659
Nessus Name: Debian dla-4476 : linux-config-6.1 - security update

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.160/6.6.120/6.12.64/6.18.3/6.19-rc1
Patch: 0b8b353e09888bccee405e0dd6feafb60360f478/d285517429a75423789e6408653e57b6fdfc8e54/74883565c621eec6cd2e35fe6d27454cf2810c23/f83e3e9f89181b42f6076a115d767a7552c4a39e/82d12088c297fa1cef670e1718b3d24f414c23f7

Timelineinfo

12/24/2025 CVE reserved
01/13/2026 +20 days Advisory disclosed
01/13/2026 +0 days VulDB entry created
03/27/2026 +73 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-68797 (🔒)
GCVE (CVE): GCVE-0-2025-68797
GCVE (VulDB): GCVE-100-340645
CERT Bund: WID-SEC-2026-0086 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 01/13/2026 17:35
Updated: 03/27/2026 08:01
Changes: 01/13/2026 17:35 (59), 02/12/2026 04:50 (2), 03/27/2026 08:01 (7)
Complete: 🔍
Cache ID: 216::103

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