CVE-2026-6297: 
vulnerability analysis and mitigation

CVE-2026-6297 is a use-after-free vulnerability in the Proxy component of Google Chrome, rated Critical by Chromium's security team. It was reported by researcher "heapracer" on March 17, 2026, and publicly disclosed on April 15, 2026, alongside a patch in Chrome version 147.0.7727.101. The vulnerability affects all Google Chrome versions prior to 147.0.7727.101, as well as Microsoft Edge (Chromium-based). It carries a CVSS v3.1 base score of 8.3 (High) (Chrome Releases, GitHub Advisory).

The vulnerability is classified as CWE-416 (Use After Free) and CWE-825 (Expired Pointer Dereference), occurring in Chrome's Proxy component when proxy-related memory is accessed after it has been freed (GitHub Advisory). Exploitation requires the attacker to be in a privileged network position (e.g., a man-in-the-middle position) and to deliver a crafted HTML page to the victim, who must interact with it. The memory corruption can be leveraged to achieve a sandbox escape, potentially allowing code execution outside Chrome's sandboxed renderer process. The bug was tracked internally as Chromium issue 493628982, and a $10,000 reward was paid to the reporter (Chrome Releases).

Successful exploitation allows an attacker in a privileged network position to perform a sandbox escape via a crafted HTML page, potentially achieving arbitrary code execution with the privileges of the Chrome process on the victim's system (GitHub Advisory, Red Hat Bugzilla). The CVSS scope is marked as "Changed," reflecting that a successful exploit can impact resources beyond the browser's security boundary. Confidentiality, integrity, and availability are all rated High, meaning an attacker could access sensitive data, modify system state, or cause application crashes on the affected host.

As of the time of disclosure, there is no public proof-of-concept exploit and no evidence of active in-the-wild exploitation (GitHub Advisory). The EPSS score is approximately 0.006% (0.000060), placing it in a low percentile for near-term exploitation probability. The vulnerability is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation requires a privileged network position and user interaction, which raises the bar compared to fully remote, zero-click vulnerabilities.

1. Privileged Network Positioning: The attacker positions themselves as a man-in-the-middle on the network path between the victim and a web server (e.g., via ARP spoofing, rogue Wi-Fi access point, or compromised network infrastructure).
2. Craft Malicious HTML Page: The attacker prepares a specially crafted HTML page designed to trigger the use-after-free condition in Chrome's Proxy component, causing the browser to access freed memory in a controlled manner.
3. Deliver Payload: The attacker intercepts or redirects the victim's HTTP/HTTPS traffic and injects or serves the malicious HTML page to the victim's browser.
4. Trigger User Interaction: The victim must load or interact with the malicious page in a vulnerable version of Chrome (prior to 147.0.7727.101).
5. Exploit Memory Corruption: The use-after-free condition is triggered in the Proxy component, corrupting heap memory in a way that allows the attacker to control execution flow within the renderer process.
6. Sandbox Escape: By chaining the memory corruption with additional techniques, the attacker escapes Chrome's sandbox and achieves code execution on the host system with the privileges of the Chrome process (Chrome Releases, GitHub Advisory).

• Network: Unexpected or anomalous proxy-related HTTP/HTTPS traffic interception; unusual ARP activity or rogue DHCP responses on the local network suggesting a man-in-the-middle setup; outbound connections from the Chrome process to unexpected external hosts following page load.
• Process: Unusual child processes spawned by the Chrome renderer process (e.g., cmd.exe, /bin/sh, powershell.exe, curl, wget); Chrome processes crashing with heap corruption errors or abnormal exit codes.
• Logs: Browser crash reports referencing the Proxy component or heap memory errors; system event logs showing unexpected process creation originating from Chrome's sandbox.
• File System: Unexpected files written to user-accessible directories by the Chrome process; new scheduled tasks, startup entries, or persistence mechanisms created shortly after a Chrome session.

Google has released a patch in Chrome 147.0.7727.101 (Linux) and 147.0.7727.101/102 (Windows/Mac), available as of April 15, 2026 (Chrome Releases). Microsoft Edge (Chromium-based) users should also apply the corresponding Edge update (Microsoft MSRC). Organizations should enforce automatic browser updates across all endpoints and restrict user access to untrusted networks or proxy configurations where possible. As a temporary measure, limiting exposure to untrusted network positions (e.g., enforcing VPN use, disabling automatic proxy detection) can reduce the attack surface until patching is complete.

The April 15, 2026 Chrome update, which addressed 31 security vulnerabilities including five rated Critical, received broad coverage from security media outlets including CyberSecurityNews, Heise, and The Hacker News, which highlighted the sandbox escape potential of the critical flaws (CyberSecurityNews, Heise). The CIS issued an advisory noting that multiple vulnerabilities in the update could allow arbitrary code execution (CIS Advisory). F5 Labs and Hawk-Eye also included the update in their weekly threat bulletins, reflecting the industry's attention to the breadth of the patch batch.