CVE-2026-78963 in Chrome
Summary
by MITRE • 08/26/2026
Improper input validation in Media in Google Chrome prior to 152.0.7977.65 allowed a remote attacker to potentially execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified as an improper input validation flaw within the media handling subsystem of Google Chrome prior to version 152.0.7977.65 represents a significant breach in browser security boundaries. This defect allows a remote attacker, through the delivery of a specially crafted HTML page, to potentially execute arbitrary code outside the confines of the renderer sandbox. The core technical issue stems from insufficient sanitization or type-checking mechanisms when processing media-related inputs, which are often complex and multi-layered in their parsing logic. When such malformed data is processed by the browser's media engine, it can trigger memory corruption errors, such as buffer overflows or use-after-free conditions, that bypass standard security mitigations like heap spraying protections or stack canaries designed to prevent exploitation of these types of flaws.
From a technical perspective, this vulnerability aligns with CWE-20 Improper Input Validation and potentially CWE-119 Memory Corruption based on the described impact of arbitrary code execution. The attack vector is classified as remote via network (ATT&CK T1189), where the adversary relies on social engineering or drive-by download tactics to lure a victim into visiting the malicious webpage. Once loaded, the crafted HTML exploits the parsing inconsistencies in the media component, leading to a state where control flow can be hijacked. This is particularly dangerous because Chrome employs a multi-process architecture with strict sandboxing for renderer processes. Bypassing this sandbox elevates the attacker's privileges from a restricted context to one that may have broader access to system resources, depending on how the exploit chain progresses and whether additional vulnerabilities are chained together to escape the browser environment entirely.
The operational impact of such a vulnerability is severe, as it enables full remote code execution without user interaction beyond visiting the webpage. This can lead to complete compromise of the victim's machine, including data theft, installation of persistent malware, or use of the system in botnets. The medium severity rating assigned by Chromium reflects that while exploitation requires specific conditions and potentially additional steps for sandbox escape, the potential consequences are critical due to the widespread adoption of Chrome as a primary web browser. Attackers can leverage this flaw in targeted campaigns against high-value targets who frequently interact with untrusted media content or visit compromised websites.
Mitigation strategies primarily involve updating Google Chrome to version 152.0.7977.65 or later, where the input validation logic has been corrected and memory safety issues addressed by developers. For organizations managing large fleets of devices, deploying automated patch management solutions ensures timely application of these security updates. Additionally, users should enable automatic update notifications within Chrome to ensure they are alerted immediately when new versions become available. Security teams can also implement network-level controls such as web filtering proxies that block access to known malicious domains or restrict the execution of active content in untrusted zones. Monitoring for anomalous browser behavior and utilizing endpoint detection and response tools capable of identifying sandbox escape attempts further reduces the risk posed by this vulnerability until patches are fully deployed across all endpoints.