Linux Kernel Page-Cache Uninitialized Variable Data Corruption & Root LPE

Critical Linux Kernel memory management bug in socket buffer coalescing enabling local privilege escalation to root and remote container breakouts.

EPSS Exploit Probability91.20%

98.5th percentile

Exploit Maturityactive wild

Active Weaponization

Primary VendorsLinux, Canonical (Ubuntu), Red Hat, SUSE

1 product(s) impacted

Ransomware CampaignNone documented

Threat intel association

CVSS v3.1 Vector Breakdown

Comprehensive attack metric decomposition according to FIRST specification

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

Attack Vector (AV)LOCALRemotely exploitable over network

Attack Complexity (AC)LOWNo specialized access needed

Privileges Required (PR)LOWUnauthenticated exploitation

User Interaction (UI)NONEZero-click / autonomous

Scope (S)CHANGEDSecurity authority boundary

Confidentiality (C)HIGHTotal information disclosure

Integrity (I)HIGHTotal compromise of system state

Availability (A)HIGHComplete resource denial

TechOverwatch AI Security Sentinel Analysis

Model: Gemini 2.0 Flash Security Sentinel · Generated: 2026-10-28

Executive Defense Summary

High-severity Linux Kernel vulnerability allowing local unprivileged users or compromised microservices in Kubernetes containers to corrupt read-only page caches and achieve instant root escalation.

Technical Root Cause Architecture

During socket buffer (skb) coalescing in the networking stack, uninitialized variables in the IPSec ESP handling path fail to preserve the shared-fragment marker. As a consequence, inbound packet decryption mutates memory buffers shared with the page cache, overwriting executable code or /etc/passwd in memory.

Exploitation Scenario & Attack Chain

An attacker running within a restricted Docker container sets up an IPSec socket, maps a targeted system binary into memory, and triggers packet coalescence to write root privileges directly into the page cache, executing commands as root on the host kernel.

Enterprise Blast Radius & Lateral Risk

Kubernetes multi-tenant cluster collapse: breach in a low-privilege pod directly grants root access over the underlying bare-metal or cloud worker node.

Remediation & Defense Playbook

Immediate actionable steps for DevOps, SecOps, and Security Architects

1Update kernel packages and reboot affected nodes: `apt update && apt dist-upgrade -y` or `dnf update kernel`.

2Restrict unprivileged user namespaces and unprivileged networking socket creation where possible.

3Utilize runtime security agents (e.g. Falco, Cilium Tetragon) to alert on anomalous kernel page cache modifications.

Detection Guidance & Threat Hunting

Inspect kernel logs (`dmesg`) for memory allocation warnings in `skb_coalesce` or anomalies in IPSec crypto transforms.

Sigma Detection Rule (SIEM Export)

title: Linux Kernel SKB Coalesce Exploit Detection
status: high
logsource:
  product: linux
  service: auditd
detection:
  selection:
    syscall: 'socket'
    proto: 'IPPROTO_ESP'
  condition: selection

Affected Software & CPE Matrix

Targeted versions, patched releases, and Common Platform Enumerations

Vendor	Product	Affected Versions	Fixed In
Linux	Linux Kernel	Kernel 6.1 through 6.11.x before stable commits	Linux 6.11.5 / 6.6.58 / 6.1.114

Official Advisories & Authoritative Sources

Linux Kernel Git Commit 3599e6bhttps://git.kernel.org/stable/c/3599e6b3cc1ada96883d496a50a210d3afbb6987

patch

CISA KEV Noticehttps://www.cisa.gov/known-exploited-vulnerabilities-catalog

cisa

AI Agent & Security Automation Hub

TechOverwatch provides native machine-readable endpoints for autonomous agents, Cursor, Claude, ChatGPT, and automated patch scanners.

Agent CLI Command (curl):

curl -s https://www.techoverwatch.in/api/vulnerabilities/CVE-2026-46300/raw

Raw Markdown JSON API