CVE-2026-9975: Chrome ANGLE Sandbox Escape – Out-of-Bounds Memory Vulnerability

Technical summary

CVE-2026-9975 is a high-severity out-of-bounds read/write vulnerability in ANGLE, Google's graphics abstraction layer used by Chromium-based browsers. The vulnerability, categorized under CWE-125 (Out-of-bounds Read) and CWE-787 (Out-of-bounds Write), enables a renderer-process-compromised attacker to achieve sandbox escape. The renderer process in Chrome operates in a sandboxed environment with restricted system access; successful exploitation of this memory corruption flaw permits privilege escalation and unrestricted access to system resources. The vulnerability affects Chrome versions prior to 148.0.7778.216 and requires user interaction (crafted HTML page rendering) but not explicit user permission bypass.

Business impact

Successful exploitation represents a complete security boundary collapse for affected users. An attacker who gains renderer-process access can, through this vulnerability, achieve unrestricted code execution at the system level—effectively neutralizing Chrome's sandbox defense. This amplifies the impact of any initial renderer compromise (such as a drive-by download or watering-hole attack) from process-limited damage to full system compromise, including credential theft, data exfiltration, malware installation, and lateral movement. Organizations with high-value users (developers, financial services, government) face elevated risk if attackers actively chain renderer exploits with this escape.

Affected systems

Google Chrome versions before 148.0.7778.216 on Windows, macOS, and Linux systems are vulnerable. The vulnerability affects the ANGLE library, which is integral to Chrome's hardware-accelerated graphics rendering on all supported platforms. While ANGLE is also used in other Chromium-based browsers (Edge, Opera, etc.), the primary guidance references Chrome; other Chromium derivatives should verify their version status against Chrome release notes to determine exposure.

Exploitability

Exploitation requires two preconditions: first, the attacker must already have compromised the renderer process (via a separate vulnerability or attack), and second, the user must view a crafted HTML page. The CVSS vector indicates high attack complexity (AC:H), reflecting the need for renderer compromise as a prerequisite and the requirement for specific conditions to trigger the out-of-bounds access. The vulnerability is not trivially exploitable from an unauthenticated network position; it is a post-compromise sandbox-escape technique. It is not currently tracked in CISA's Known Exploited Vulnerabilities catalog, though this does not preclude active exploitation in targeted campaigns.

Remediation

Update Google Chrome to version 148.0.7778.216 or later immediately. Chrome will automatically download the update; users should restart the browser to apply it. Administrators should enforce Chrome auto-update policies and consider restricting renderer process permissions at the OS level (using AppArmor, SELinux, or Windows security policies) as a defense-in-depth measure. Additionally, organizations should audit for and remediate any initial renderer-process vulnerabilities in their environment, as this escape is only dangerous if renderer compromise has already occurred.

Patch guidance

Google released the fix in Chrome version 148.0.7778.216 on 2026-05-28. Verify the installed version via chrome://version or the Settings > About Chrome menu; Chrome will automatically check for and install updates. Administrators managing Chrome deployments should push this version via enterprise update channels (Google Admin Console, Group Policy, or mobile device management). Test patches in a non-production environment first to confirm compatibility with line-of-business web applications and extensions, though this is a security-critical update warranting rapid deployment.

Detection guidance

Monitor Chrome version compliance across your environment using endpoint management or browser telemetry tools to identify systems still running versions prior to 148.0.7778.216. Watch for suspicious sandbox-escape indicators: unexpected system-level process spawning from chrome.exe/chromium, unusual file system or registry modifications originating from the Chrome process, or crash reports citing ANGLE library functions. Correlate with renderer crash logs or exploit activity in web traffic logs. Behavioral detection of post-renderer-compromise activity (e.g., credential enumeration, lateral movement from a Chrome process) may flag exploitation attempts. Consider enabling Chrome's crash reporting to centralize detection signals.

Why prioritize this

This vulnerability merits immediate patching despite not being in the KEV catalog. The combination of high CVSS score (8.3), sandbox-escape capability (elevating impact), and applicability across all major operating systems creates substantial organizational risk. While it requires renderer compromise as a prerequisite, the ease with which renderer vulnerabilities are discovered and exploited makes this an attractive chaining target for sophisticated attackers. Organizations with users accessing untrusted or adversary-controlled web content should deprioritize zero-day browser bugs even more aggressively.

Risk score, explained

The CVSS 3.1 score of 8.3 (HIGH) reflects high impact (confidentiality, integrity, and availability all rated HIGH) but high attack complexity (AC:H) due to the renderer-compromise prerequisite. The vulnerability does not require authentication (PR:N) but does require user interaction (UI:R) to view the crafted page. The scope is changed (S:C), indicating the impact extends beyond the vulnerable component (the sandbox) to the broader system. The score appropriately penalizes the conditional nature (renderer must already be compromised) while recognizing that, given that condition, complete system compromise is likely.

Frequently asked questions