CVE-2026-118311 in Chrome
Summary
by MITRE • 10/28/2026
Memory corruption in Media in Google Chrome prior to 156.0.8078.73 allowed a remote attacker to potentially execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/28/2026
The vulnerability described involves a critical memory corruption flaw within the media processing subsystem of Google Chrome, specifically in versions prior to 156.0.8078.73. This type of defect typically arises from improper handling of data structures during the decoding or rendering of multimedia content, such as video streams or audio files embedded via HTML tags like <video> or <audio>. When a user visits a maliciously crafted webpage containing specially constructed media assets, the browser's internal components may misinterpret memory boundaries. This leads to conditions where writes occur outside allocated buffers, resulting in heap corruption or stack overflow scenarios that compromise the integrity of adjacent memory regions. The severity is classified as High by Chromium security standards due to the potential for remote code execution without user interaction beyond visiting a webpage.
From a technical perspective, this flaw represents an out-of-bounds write or use-after-free condition within the media pipeline. Attackers can exploit these memory safety violations to overwrite function pointers, vtables, or other critical control data structures located in nearby memory locations. By carefully crafting the payload embedded in the HTML page, it is possible to achieve arbitrary code execution within the context of the browser process. Although modern browsers employ sandboxing techniques to restrict the privileges of renderer processes and limit the impact of such exploits, sophisticated attackers may combine this vulnerability with other primitives or kernel-level flaws to escape the sandbox environment entirely. The presence of mitigations like ASLR (Address Space Layout Randomization) and DEP/NX (Data Execution Prevention) makes exploitation more difficult but does not eliminate the risk if memory corruption allows for reliable control flow hijacking.
The operational impact of this vulnerability is severe, as it enables a remote attacker to execute arbitrary code on the victim's machine with the privileges of the browser process. This can lead to full system compromise depending on the effectiveness of the sandbox and subsequent privilege escalation attempts. Attackers could install malware, steal sensitive data such as cookies or session tokens, monitor user activity, or use the compromised device for further attacks in a botnet. The attack vector is classified as remote via network (HTTP/HTTPS), requiring no special privileges from the attacker other than hosting the malicious webpage and convincing a target to visit it. This aligns with common web-based attack patterns where social engineering plays a significant role in initial access, although automated drive-by download techniques can also be employed.
In terms of industry standards, this vulnerability maps closely to CWE-120 (Buffer Copy without Checking Size of Input) or CWE-416 (Use After Free), depending on the specific nature of the memory corruption. It is also associated with MITRE ATT&CK technique T1203 (Exploitation for Client Execution), which describes adversaries exploiting software vulnerabilities to execute code on client systems. The exploitation chain likely involves initial access through a crafted web page, followed by execution within the browser sandbox, and potentially privilege escalation if additional vectors are available. Security researchers often analyze such flaws using fuzzing tools that generate malformed media files to trigger these memory errors during parsing or decoding phases.
To mitigate this risk, organizations should ensure that all instances of Google Chrome are updated to version 156.0.8078.73 or later immediately upon availability. Patch management processes must be rigorous and automated where possible to minimize the window of exposure. For users unable to update immediately, enabling strict content security policies (CSP) can help restrict inline scripts and potentially limit some attack surfaces, though it may not fully prevent media-based exploits if they rely on native browser components rather than JavaScript. Additionally, deploying endpoint detection and response (EDR) solutions with behavioral analysis capabilities can help detect anomalous processes spawned by the browser that indicate successful exploitation attempts. Regular security awareness training for users regarding suspicious links and websites remains a vital layer of defense against social engineering tactics used to deliver such payloads.