CVE-2026-46243VulnerabilityPublished 4 Jun 2026Updated 9 Oct 2026

Red Hat Security Advisory: kernel-rt security update

Affects Linux kernelSource GCVE Database

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Mentioned vulnerabilities

CVE-2026-46331

Not known to be exploited : upgrade Linux kernel to 10.2.0 or 9.8.0 soon.

Data as of 30 Oct 2026, 11:52 UTC

Severity

High

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.4% chance of exploitation in 30 days – higher than 35% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 10.2.0, 9.8.0

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to 10.2.0 or 9.8.0.

Affected software

Product	Affected	Fixed in
Red Hat Product Security Red Hat	Affected >=9.0.0 <9.8.0 >=10.0.0 <10.2.0 Red Hat Red Hat Enterprise Linux Red Hat Enterprise Linux BaseOS (v. 8) Red Hat Enterprise Linux CRB (v. 8) aarch64 Red Hat Enterprise Linux NFV (v. 8) Red Hat Enterprise Linux RT (v. 8) src Red Hat Enterprise Linux for NVIDIA NVIDIA for RHEL 10 kernel-0:6.12.0-212.9.el10nv.src Red Hat OpenShift Enterprise Red Hat OpenShift Container Platform 4.18 rhcos-aarch64-418.94.202606250458-0	Fixed in 9.8.0 10.2.0

AI-suggested

Red Hat has released official live patch updates (kpatch-patch-5_14_0-687_10_1 for RHEL 9 and kpatch-patch-6_12_0-211_16_1 for RHEL 10) that address CVE-2026-46243 and CVE-2026-46331. Users should apply these updates following Red Hat's guidance at https://access.redhat.com/articles/11258. The patches are available for multiple architectures and product variants. Applying these official patches fully mitigates the vulnerability.

Description

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements. Security Fix(es): * kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions (CVE-2026-46243) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Impact

The vulnerability affects the Linux kernel SMB client component in Red Hat Enterprise Linux, potentially allowing improper handling of userspace cifs.spnego descriptions. This could lead to security issues rated as high severity by Red Hat. No known exploits in the wild have been reported. The impact is mitigated by applying the provided kernel live patch updates.

Summary

The Linux kernel packages in Red Hat Enterprise Linux contain a vulnerability identified as CVE-2026-46243 affecting the SMB client, specifically in handling userspace cifs.spnego descriptions. This issue is addressed by rejecting such descriptions to prevent potential misuse. The fix is delivered via kpatch live patch modules for kernel versions 5.14.0-687.10.1.el9_8 and 6.12.0-211.16.1.el10_2. The advisory also includes a fix for CVE-2026-46331 related to net/sched act_pedit. Red Hat provides updated kpatch packages for multiple architectures and variants of RHEL 9 and 10. The advisory references official Red Hat documentation for applying these updates.

CWE-20Improper Input Validation (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #18OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Attack Surface Reduction
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of…
Architecture and Design · Libraries or Frameworks
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Server Side Include (SSI) Injection (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Command Line Execution through SQL Injection (opens in a new tab)
Object Relational Mapping Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-825Expired Pointer Dereference (opens in a new tab)
Base weakness
The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.
Architecture and Design
Choose a language that provides automatic memory management.
Implementation
When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Aug 2026, 00:07 UTC

Public exploits and detectionGitHub proofs of concept

WeaknessesCWE-20, CWE-825

Technical details

References

Community reviews

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