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7.8
HIGH CVSS 3.1
CVE-2026-46243
smb: client: reject userspace cifs.spnego descriptions
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: reject userspace cifs.spnego descriptions cifs.spnego key descriptions contain authority-bearing fields such as pid, uid, creduid, and upcall_target that cifs.upcall treats as kernel-originating inputs. However, userspace can also create keys of this type through request_key(2) or add_key(2), allowing those fields to be supplied without CIFS origin. Only accept cifs.spnego descriptions while CIFS is using its private spnego_cred to request the key.

Details
INFO

Published Date :

June 1, 2026, 5:17 p.m.

Last Modified :

June 9, 2026, 8:47 p.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Impact
Affected Products

The following products are affected by CVE-2026-46243 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
Limit cifs.spnego key descriptions to prevent unauthorized access.
  • Update the Linux kernel to include the fix.
  • Ensure CIFS uses private spnego_cred for key requests.
  • Monitor key creation for unauthorized sources.
Public PoC/Exploit Available at Github

CVE-2026-46243 has a 12 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-46243.

URL Resource
https://git.kernel.org/stable/c/0aece6685fc80a8de492688ca2315fb86ec379c7 Patch
https://git.kernel.org/stable/c/2035acfb17221729b1b8ac335e941868a04ca079 Patch
https://git.kernel.org/stable/c/3da1fdf4efbc490041eb4f836bf596201203f8f2 Patch
https://git.kernel.org/stable/c/7713bd320ed4fc3d08a227cd8e41242219a16981 Patch
https://git.kernel.org/stable/c/91f89c1d83e80417629791fcef6af8140d7d01c8 Patch
https://git.kernel.org/stable/c/9544559e59438a4b609b2fdfa0763d8360572824 Patch
https://git.kernel.org/stable/c/a3bbda6502a9398b816fa2e71c9a3f955f58013d Patch
https://git.kernel.org/stable/c/cf20038657d6d4974349556a34e08fe0490bebbc Patch
http://www.openwall.com/lists/oss-security/2026/06/01/6 Mailing List Third Party Advisory
https://github.com/manizada/CIFSwitch Third Party Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-46243 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-46243 weaknesses.

CAPEC-3: Using Leading 'Ghost' Character Sequences to Bypass Input Filters Using Leading 'Ghost' Character Sequences to Bypass Input Filters CAPEC-7: Blind SQL Injection Blind SQL Injection CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-13: Subverting Environment Variable Values Subverting Environment Variable Values CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow CAPEC-22: Exploiting Trust in Client Exploiting Trust in Client CAPEC-23: File Content Injection File Content Injection CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow CAPEC-28: Fuzzing Fuzzing CAPEC-31: Accessing/Intercepting/Modifying HTTP Cookies Accessing/Intercepting/Modifying HTTP Cookies CAPEC-42: MIME Conversion MIME Conversion CAPEC-43: Exploiting Multiple Input Interpretation Layers Exploiting Multiple Input Interpretation Layers CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion CAPEC-52: Embedding NULL Bytes Embedding NULL Bytes CAPEC-53: Postfix, Null Terminate, and Backslash Postfix, Null Terminate, and Backslash CAPEC-63: Cross-Site Scripting (XSS) Cross-Site Scripting (XSS) CAPEC-64: Using Slashes and URL Encoding Combined to Bypass Validation Logic Using Slashes and URL Encoding Combined to Bypass Validation Logic CAPEC-67: String Format Overflow in syslog() String Format Overflow in syslog() CAPEC-71: Using Unicode Encoding to Bypass Validation Logic Using Unicode Encoding to Bypass Validation Logic CAPEC-72: URL Encoding URL Encoding CAPEC-73: User-Controlled Filename User-Controlled Filename CAPEC-78: Using Escaped Slashes in Alternate Encoding Using Escaped Slashes in Alternate Encoding CAPEC-79: Using Slashes in Alternate Encoding Using Slashes in Alternate Encoding CAPEC-80: Using UTF-8 Encoding to Bypass Validation Logic Using UTF-8 Encoding to Bypass Validation Logic CAPEC-81: Web Server Logs Tampering Web Server Logs Tampering CAPEC-83: XPath Injection XPath Injection CAPEC-85: AJAX Footprinting AJAX Footprinting CAPEC-88: OS Command Injection OS Command Injection CAPEC-101: Server Side Include (SSI) Injection Server Side Include (SSI) Injection CAPEC-104: Cross Zone Scripting Cross Zone Scripting CAPEC-108: Command Line Execution through SQL Injection Command Line Execution through SQL Injection CAPEC-109: Object Relational Mapping Injection Object Relational Mapping Injection CAPEC-110: SQL Injection through SOAP Parameter Tampering SQL Injection through SOAP Parameter Tampering CAPEC-120: Double Encoding Double Encoding CAPEC-135: Format String Injection Format String Injection CAPEC-136: LDAP Injection LDAP Injection CAPEC-153: Input Data Manipulation Input Data Manipulation CAPEC-182: Flash Injection Flash Injection CAPEC-209: XSS Using MIME Type Mismatch XSS Using MIME Type Mismatch CAPEC-230: Serialized Data with Nested Payloads Serialized Data with Nested Payloads CAPEC-231: Oversized Serialized Data Payloads Oversized Serialized Data Payloads CAPEC-250: XML Injection XML Injection CAPEC-261: Fuzzing for garnering other adjacent user/sensitive data Fuzzing for garnering other adjacent user/sensitive data CAPEC-267: Leverage Alternate Encoding Leverage Alternate Encoding CAPEC-473: Signature Spoof Signature Spoof CAPEC-588: DOM-Based XSS DOM-Based XSS CAPEC-664: Server Side Request Forgery Server Side Request Forgery

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

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liamromanis101/k8s-container-escape-audit-lite

Free read-only container escape and Kubernetes security audit. 23 checks covering privileged mode, capabilities, namespace isolation, runtime sockets, service accounts, cloud IMDS and kubelet API. JSON output, CI/CD ready. Pro version (47 checks + CVE engine) on Capafy.

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liamromanis101/cifswitch-check

Detection script for CIFSwitch - CVE-2026-46243

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MrForkBomb/CIFSwitch-Checker-CVE-2026-46243

Script para comprobar si la vulnerabilidad de Linux CIFSwitch (CVE-2026-46243) nos afecta. Detecta configuraciones potencialmente vulnerables y mitigaciones sin ejecutar exploits.

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Koshmare-Blossom/CIFSwitch-go

A Go implementation of CIFSwitch (CVE-2026-46243)

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Updated: 2 weeks, 5 days ago
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suominen/cifswitch

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Updated: 2 weeks, 2 days ago
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manizada/CIFSwitch

None

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Updated: 2 weeks, 2 days ago
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cbovin/linux-lpe-pocs

Linux local privilege escalation PoCs and mitigations.

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GYscan是一款基于Go语言开发的现代化综合渗透测试工具，专为安全研究人员、渗透测试工程师和红队成员设计。项目采用模块化架构，包含C2服务器端和客户端组件，支持Windows和Linux平台，提供系统安全分析和漏洞扫描功能。

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raesene/vuln_pocs

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Updated: 1 week, 1 day ago
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nomi-sec/PoC-in-GitHub

📡 PoC auto collect from GitHub. ⚠️ Be careful Malware.

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Born at : Dec. 8, 2019, 1:03 p.m. This repo has been linked 718 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-46243 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-46243 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Jun. 09, 2026

    Action Type Old Value New Value
    Added CWE NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:2.6.24:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.24:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.24:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.24:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.24:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.24:rc8:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.24:-:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.175 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.209 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.92 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.34 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.24.1 up to (excluding) 5.10.258 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.11 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.142
    Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/06/01/6 Types: Mailing List, Third Party Advisory
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/0aece6685fc80a8de492688ca2315fb86ec379c7 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/2035acfb17221729b1b8ac335e941868a04ca079 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/3da1fdf4efbc490041eb4f836bf596201203f8f2 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/7713bd320ed4fc3d08a227cd8e41242219a16981 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/91f89c1d83e80417629791fcef6af8140d7d01c8 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/9544559e59438a4b609b2fdfa0763d8360572824 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/a3bbda6502a9398b816fa2e71c9a3f955f58013d Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/cf20038657d6d4974349556a34e08fe0490bebbc Types: Patch
    Added Reference Type CISA-ADP: https://github.com/manizada/CIFSwitch Types: Third Party Advisory
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jun. 05, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Jun. 01, 2026

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2026/06/01/6
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 01, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-20
    Added Reference https://github.com/manizada/CIFSwitch
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jun. 01, 2026

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: smb: client: reject userspace cifs.spnego descriptions cifs.spnego key descriptions contain authority-bearing fields such as pid, uid, creduid, and upcall_target that cifs.upcall treats as kernel-originating inputs. However, userspace can also create keys of this type through request_key(2) or add_key(2), allowing those fields to be supplied without CIFS origin. Only accept cifs.spnego descriptions while CIFS is using its private spnego_cred to request the key.
    Added Reference https://git.kernel.org/stable/c/0aece6685fc80a8de492688ca2315fb86ec379c7
    Added Reference https://git.kernel.org/stable/c/2035acfb17221729b1b8ac335e941868a04ca079
    Added Reference https://git.kernel.org/stable/c/3da1fdf4efbc490041eb4f836bf596201203f8f2
    Added Reference https://git.kernel.org/stable/c/7713bd320ed4fc3d08a227cd8e41242219a16981
    Added Reference https://git.kernel.org/stable/c/91f89c1d83e80417629791fcef6af8140d7d01c8
    Added Reference https://git.kernel.org/stable/c/9544559e59438a4b609b2fdfa0763d8360572824
    Added Reference https://git.kernel.org/stable/c/a3bbda6502a9398b816fa2e71c9a3f955f58013d
    Added Reference https://git.kernel.org/stable/c/cf20038657d6d4974349556a34e08fe0490bebbc
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 7.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact