CVE-2026-106318 in Chrome
Summary
by MITRE • 10/06/2026
Use after free in Media in Google Chrome prior to 155.0.8059.39 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as a use-after-free condition within the media subsystem of Google Chrome prior to version 155.0.8059.39 represents a critical memory management flaw that compromises the integrity of the browser's sandboxing mechanisms. This type of error occurs when an application continues to use a pointer after the memory it points to has been freed, leading to undefined behavior that can be exploited by malicious actors. In this specific instance, the flaw resides in how Chrome handles media resources, which are often processed through complex pipelines involving decoding, rendering, and state management components. When these components interact improperly during resource deallocation, they may retain references to memory regions that have already been released back to the system allocator. This creates a window of opportunity for an attacker to manipulate the contents of that freed memory before it is reallocated for other purposes, thereby gaining control over program execution flow or data integrity within the browser process.
From a technical perspective, use-after-free vulnerabilities are particularly dangerous because they allow attackers to achieve arbitrary code execution with high reliability when combined with specific exploitation techniques such as heap spraying or object reuse attacks. The attacker crafts an HTML page that triggers the premature release of media-related objects while maintaining references to those same objects through other active components within the browser engine. By carefully controlling the allocation patterns in the heap, the adversary can force the system to allocate maliciously crafted data structures into the freed memory slots. When the vulnerable code subsequently accesses these stale pointers, it inadvertently operates on the attacker-controlled data rather than legitimate media resources. This misdirection enables the injection and execution of arbitrary shellcode or exploit payloads within the context of the Chrome renderer process, effectively bypassing standard security controls that rely on correct memory state assumptions.
The operational impact of this vulnerability is severe due to its potential for remote code execution via a simple web interaction. Since the flaw allows an attacker to execute code inside the sandboxed environment of the browser, it undermines one of the primary defenses against malware and data theft in modern browsers. Although Chrome employs multiple layers of security including site isolation, job objects on Windows, and memory protection features like DEP and ASLR, a successful exploitation of this use-after-free condition can lead to full compromise of the renderer process. In many configurations, especially if additional vulnerabilities are chained or if sandbox escape techniques are employed, this could escalate to system-level access. The threat is exacerbated by the fact that media processing often involves complex code paths with numerous entry points and state transitions, making it difficult for static analysis tools to detect all potential race conditions or logic errors related to memory lifecycle management without deep dynamic instrumentation.
This vulnerability aligns closely with CWE-416, which defines use after free as a class of software defects where pointers are used after they have been freed, leading to unpredictable behavior and security breaches. Furthermore, the exploitation vector maps directly to MITRE ATT&CK technique T1203, specifically referencing exploit for client-side code execution through web browsers. The attack scenario described involves delivering malicious content via a crafted HTML page, which corresponds to initial access vectors often seen in drive-by download attacks or phishing campaigns where users are tricked into visiting compromised websites. The high severity rating assigned by the Chromium security team reflects both the ease of exploitation given mature exploit development techniques and the significant impact on user confidentiality and system integrity if left unpatched.
Mitigation strategies primarily involve applying the official patch provided in Google Chrome version 155.0.8059.39 or later, which corrects the memory management logic to ensure that pointers are nullified immediately after deallocation and prevents access to freed media objects. Organizations should enforce automatic update policies for all endpoints running this browser to minimize exposure windows. Additionally, security teams can implement application control solutions such as Microsoft AppLocker or Windows Defender Application Control to restrict the execution of untrusted scripts within browser processes. Network-level defenses like web filtering proxies can also be configured to block access to known malicious domains hosting exploit kits that target this specific vulnerability. Regular monitoring for anomalous memory usage patterns in endpoint detection and response systems may help identify attempted exploitation activities, although proactive patching remains the most effective defense against such client-side vulnerabilities.