Cyber Posture

CVE-2026-5858

High

Published: 08 April 2026

Published
08 April 2026
Modified
13 April 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0009 24.9th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-5858 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Google Chrome. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 24.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Drive-by Compromise (T1189) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Mandates timely remediation of the heap buffer overflow vulnerability through patching Google Chrome to version 147.0.7727.55 or later.

prevent

Provides memory safeguards like ASLR and DEP that directly mitigate heap buffer overflow exploits enabling arbitrary code execution in WebML.

prevent

Enforces browser process isolation and sandboxing to contain arbitrary code execution within the renderer process triggered by the crafted HTML page.

MITRE ATT&CK Enterprise TechniquesAI

T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Why these techniques?

Heap buffer overflow in Chrome WebML enables arbitrary code execution via malicious HTML page visited by user, directly mapping to Drive-by Compromise (T1189) for initial access and Exploitation for Client Execution (T1203) for browser RCE.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Heap buffer overflow in WebML in Google Chrome prior to 147.0.7727.55 allowed a remote attacker to execute arbitrary code via a crafted HTML page. (Chromium security severity: Critical)

Deeper analysisAI

CVE-2026-5858 is a heap buffer overflow vulnerability (CWE-122) in the WebML component of Google Chrome versions prior to 147.0.7727.55. Published on 2026-04-08, this critical issue carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), enabling potential arbitrary code execution.

A remote attacker can exploit the vulnerability by crafting an HTML page that triggers the heap buffer overflow in WebML when rendered in an affected Chrome browser. Exploitation requires user interaction, such as visiting the malicious page, but no privileges or special access, allowing the attacker to execute arbitrary code with high-impact consequences on confidentiality, integrity, and availability within the browser's context.

The Chrome Releases stable channel update for desktop and Chromium issue 493319454 detail the patch, with mitigation achieved by upgrading to Google Chrome 147.0.7727.55 or later.

Details

CWE(s)

Affected Products

google
chrome
≤ 147.0.7727.55

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References