CVE-2026-78975 in Chrome
Summary
by MITRE • 08/26/2026
Incorrect authorization in DOM in Google Chrome prior to 152.0.7977.65 allowed a remote attacker to obtain sensitive information 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 incorrect authorization issue within the Document Object Model of Google Chrome represents a significant breach in browser-side access control mechanisms. This flaw, present in versions prior to 152.0.7977.65, stems from improper validation checks when handling cross-origin requests or DOM manipulation operations. In modern web architectures, browsers enforce strict same-origin policies to prevent malicious scripts on one site from accessing data belonging to another. However, this specific implementation error allowed a remote attacker to bypass these restrictions by crafting a specialized HTML page that exploited the lax authorization logic within the rendering engine. The core technical flaw lies in the failure of the browser's security boundary checks during DOM traversal or property access, effectively granting unauthorized read privileges to sensitive information such as cookies, local storage data, or internal state variables from other domains.
From an operational perspective, this vulnerability enables a remote code execution scenario that does not require user interaction beyond visiting a maliciously crafted webpage. An attacker could host the exploit on a third-party site and lure victims through phishing campaigns or drive-by downloads. Once executed, the script can exfiltrate sensitive user data to the attacker's server without triggering standard security warnings. This capability undermines the fundamental trust model of web browsing, where users expect their session tokens and personal information to remain isolated from untrusted sources. The severity is classified as medium by Chromium because while it allows for significant data leakage, it typically does not provide direct arbitrary code execution on the host system but rather facilitates further attacks through stolen credentials or session hijacking.
This vulnerability aligns closely with CWE-269, which describes Improper Authorization, specifically in contexts where access control checks are bypassed due to logic errors. It also maps to MITRE ATT&CK technique T1530, Data from Local System, as the attacker is retrieving data stored locally within the browser environment but belonging to other applications or sites. The exploitation vector relies on social engineering to direct users to the crafted HTML page, leveraging the user's authenticated sessions with various web services. By manipulating the DOM in ways that were not anticipated by the security model, the attacker can read properties and values that should have been restricted to their respective origins.
Mitigation strategies primarily involve updating Google Chrome to version 152.0.7977.65 or later, where these authorization checks have been hardened to correctly enforce origin boundaries during DOM operations. For organizations deploying Chrome via enterprise policies, ensuring automatic updates are enabled is critical to closing this window of exposure. Additionally, developers should implement Content Security Policy headers that restrict the execution of inline scripts and limit data exfiltration channels through directives like script-src and connect-src. While technical mitigations within the browser address the root cause, user awareness remains a secondary defense layer; educating users about the risks of visiting untrusted sites can reduce the likelihood of successful exploitation in environments where immediate patching is not feasible.