CVE-2026-79255 in Chrome
Summary
by MITRE • 08/26/2026
Improper input validation in WebRTC in Google Chrome prior to 152.0.7977.65 allowed a remote attacker who had compromised the renderer process to bypass web origin policy 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 WebRTC implementation of Google Chrome prior to version 152.0.7977.65 represents a significant breach in browser isolation mechanisms. This issue specifically affects the rendering process, which is responsible for executing web content such as HTML, JavaScript, and media streams. The core technical deficiency lies in how the WebRTC subsystem processes input data related to network connections and media handling. When an attacker crafts a malicious HTML page designed to exploit this specific validation gap, they can manipulate internal state variables or memory structures associated with WebRTC operations. This manipulation allows the crafted content to perform actions that should be restricted by standard web security models, effectively breaking the boundaries intended to keep different origins isolated from one another.
From an operational perspective, the impact of this vulnerability is centered on the bypassing of the same-origin policy. The same-origin policy is a critical security concept implemented in web browsers that restricts how a document or script loaded from one origin can interact with resources from another origin. By exploiting this input validation error, a remote attacker who has already compromised the renderer process through other means can escalate their privileges within the browser environment. This compromise allows the malicious code to access sensitive data, such as cookies, local storage contents, or DOM elements belonging to different websites that the user is currently viewing. The severity of this issue is classified as medium by Chromium security standards because it requires an initial foothold in the renderer process rather than a direct remote code execution from untrusted content alone, yet it significantly degrades the overall trust model of the browser.
This vulnerability aligns with common weakness enumerations related to input validation failures and access control issues. Specifically, it relates to CWE-20 Improper Input Validation, where insufficient checks allow malformed or malicious data to trigger unintended behavior in system components. Furthermore, the exploitation technique maps directly to MITRE ATT&CK techniques involving browser security bypasses, particularly those that leverage renderer process compromises to violate origin isolation principles. Attackers often use such vulnerabilities as part of a broader attack chain, following initial compromise via phishing or drive-by downloads, to exfiltrate sensitive user data or perform actions on behalf of the victim across multiple domains without detection by standard browser safeguards.
Mitigation for this vulnerability primarily involves updating Google Chrome to version 152.0.7977.65 or later, where these input validation checks have been hardened and corrected. For organizations managing large fleets of devices, automated patch management systems should be configured to prioritize updates containing security fixes related to browser components. Additionally, users can employ additional layers of defense such as strict content security policies on their own websites to limit the capabilities of scripts even if a renderer is compromised. Security teams should also monitor for indicators of compromise that suggest attempts to exploit WebRTC-related flaws, including unusual network traffic patterns or unexpected access to cross-origin resources by web applications running in the browser environment.