CVE-2026-43452

Description

A flaw was found in the Linux kernel's netfilter component, specifically within the xt_tcpudp and xt_dccp option walkers. When processing network packet options, a 1-byte tail read vulnerability allows the system to access memory beyond the intended buffer. This out-of-bounds read could potentially lead to information disclosure or a denial of service.

Statement

Red Hat acknowledges the upstream Linux kernel correction for «netfilter» as described in COMMENT_ZERO. Fixes are delivered through standard kernel errata for supported products. Operational exposure depends on whether this subsystem or driver is active in your configuration.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score5.5N/A8.2
Attack VectorLocalN/ANetwork
Attack ComplexityLowN/ALow
Privileges RequiredLowN/ANone
User InteractionNoneN/ANone
ScopeUnchangedN/AUnchanged
ConfidentialityNoneN/ALow
Integrity ImpactNoneN/ANone
Availability ImpactHighN/AHigh

Vector

Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Instability

This weakness will generally lead to undefined behavior and therefore crashes. In the case of overflows involving loop index variables, the likelihood of infinite loops is also high.

Integrity

Technical Impact: Modify Memory

If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the wrap around results in other conditions such as buffer overflows, further memory corruption may occur.

Confidentiality,Availability,Access Control

Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism

This weakness can sometimes trigger buffer overflows which can be used to execute arbitrary code. This is usually outside the scope of a program's implicit security policy.

Frequently Asked Questions

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