CVE-2026-4674 in Chrome
Summary
by MITRE • 03/24/2026
Out of bounds read in CSS in Google Chrome prior to 146.0.7680.165 allowed a remote attacker to perform out of bounds memory access via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 03/28/2026
This vulnerability represents a critical out of bounds read condition within Google Chrome's CSS rendering engine that existed prior to version 146.0.7680.165. The flaw manifests when the browser processes specially crafted HTML pages containing malicious CSS content, creating a scenario where memory access occurs beyond the allocated buffer boundaries. Such out of bounds reads typically arise from insufficient input validation or boundary checking within the CSS parser implementation, allowing attackers to access memory locations that should remain protected from direct access. The vulnerability falls under the category of memory safety issues and aligns with common weakness enumerations such as CWE-125, which specifically addresses out of bounds read conditions in software implementations.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides remote attackers with the potential to execute arbitrary code or cause denial of service conditions within the affected browser environment. When Chrome encounters malformed CSS data during page rendering, the parser fails to properly validate array indices or buffer limits, enabling attackers to craft HTML documents that trigger memory access violations. This type of vulnerability can be exploited through various attack vectors including malicious websites, phishing campaigns, or compromised web applications that serve the crafted content to unsuspecting users. The high severity classification according to Chromium security standards indicates the potential for significant compromise given the ease of exploitation through standard web browsing activities.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1059.001 for command and control through web services, and potentially T1211 for exploitation of memory corruption vulnerabilities. The attack surface is particularly concerning as it leverages the most common user interaction method - web browsing - to deliver malicious payloads. The vulnerability demonstrates how seemingly benign web content can be weaponized to exploit fundamental memory safety issues within browser implementations. Security researchers have noted that such out of bounds read vulnerabilities often serve as stepping stones to more sophisticated attacks, as they can be chained with other exploits to achieve privilege escalation or information disclosure. The affected component specifically targets the CSS engine's parsing logic, which is critical for rendering web page visual elements and handling user-defined styling rules.
Mitigation strategies should prioritize immediate patch deployment to versions 146.0.7680.165 and later, as this represents the definitive fix for the memory access violation. Organizations should implement network-level protections including web application firewalls and content filtering systems that can detect and block suspicious CSS content. Browser hardening measures such as enabling sandboxing, disabling unnecessary browser features, and implementing strict content security policies can reduce the attack surface. Security monitoring should include detection of unusual memory access patterns and potential exploitation attempts through network traffic analysis. Additionally, user education regarding safe browsing practices and awareness of phishing attempts remains crucial, as social engineering often complements technical exploitation methods. The vulnerability underscores the importance of regular security updates and continuous monitoring of browser security patches to prevent exploitation of known memory safety issues in web rendering engines.