Linux Kernel up to 6.6.135/6.12.82/6.18.23/6.19.13 SMB Client cifs_sanitize_prepath out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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6.1$0-$5k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.6.135/6.12.82/6.18.23/6.19.13. This vulnerability affects the function cifs_sanitize_prepath of the component SMB Client. The manipulation results in out-of-bounds. This vulnerability is known as CVE-2026-43112. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.135/6.12.82/6.18.23/6.19.13. It has been classified as problematic. Affected is the function cifs_sanitize_prepath of the component SMB Client. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath When cifs_sanitize_prepath is called with an empty string or a string containing only delimiters (e.g., "/"), the current logic attempts to check *(cursor2 - 1) before cursor2 has advanced. This results in an out-of-bounds read. This patch adds an early exit check after stripping prepended delimiters. If no path content remains, the function returns NULL. The bug was identified via manual audit and verified using a standalone test case compiled with AddressSanitizer, which triggered a SEGV on affected inputs.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-43112 since 05/01/2026. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 322088 (Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2026-1882)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.136, 6.12.83, 6.18.24 or 6.19.14 eliminates this vulnerability. Applying the patch 5d4fe469fe7dbff7d874c196bb680a82f2625d95/2d29214448ec0f4e7e18bb1c14dd4a6c07f1c439/86f9c23e0814cfdffda9eedf0c591c51ba209010/49b1ce6d7cfb6c5a49f68bf5ccfcfb6ba14e63c3/78ec5bf2f589ec7fd8f169394bfeca541b077317 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 (322088) and CERT Bund (WID-SEC-2026-1385). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • Microsoft Azure Linux

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.1
VulDB Meta Temp Score: 6.1

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.8
CNA Vector (Linux): 🔒

CVSSv2info

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

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 322088
Nessus Name: Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2026-1882)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.136/6.12.83/6.18.24/6.19.14
Patch: 5d4fe469fe7dbff7d874c196bb680a82f2625d95/2d29214448ec0f4e7e18bb1c14dd4a6c07f1c439/86f9c23e0814cfdffda9eedf0c591c51ba209010/49b1ce6d7cfb6c5a49f68bf5ccfcfb6ba14e63c3/78ec5bf2f589ec7fd8f169394bfeca541b077317

Timelineinfo

05/01/2026 CVE reserved
05/06/2026 +5 days Advisory disclosed
05/06/2026 +0 days VulDB entry created
06/24/2026 +49 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-43112 (🔒)
GCVE (CVE): GCVE-0-2026-43112
GCVE (VulDB): GCVE-100-361320
CERT Bund: WID-SEC-2026-1385 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 05/06/2026 12:50
Updated: 06/24/2026 20:35
Changes: 05/06/2026 12:50 (59), 06/04/2026 13:25 (11), 06/09/2026 00:28 (7), 06/24/2026 20:35 (2)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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