CVE-2026-106390 in Chrome
Summary
by MITRE • 10/07/2026
Incorrect provision of specified functionality in SanitizerAPI in Google Chrome prior to 155.0.8059.39 allowed a remote attacker to leak sensitive information via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as an incorrect provision of specified functionality within the SanitizerAPI in Google Chrome prior to version 155.0.8059.39 represents a significant flaw in how browser-side content sanitization is executed during HTML processing. The Sanitizer API, introduced to provide web developers with a standardized method for safely cleaning untrusted HTML strings before rendering them into the DOM, relies on strict adherence to defined rules regarding allowed tags and attributes. In this specific instance, the implementation failed to correctly enforce these constraints under certain conditions, allowing crafted input to bypass expected sanitization boundaries. This failure creates an avenue for information leakage where sensitive data embedded within or associated with the processed HTML content can be exposed to contexts that should not have access to it.
From a technical perspective, this flaw aligns closely with CWE-20 Improper Input Validation and potentially CWE-798 Use of Hard-coded Credentials if the leaked information involves authentication tokens or session identifiers stored in local storage or cookies accessible via DOM manipulation. The root cause lies in the logic governing how the Sanitizer API filters out dangerous elements such as script tags, event handlers, or specific attribute values that could facilitate cross-site scripting (XSS) attacks. When this filtering mechanism is bypassed due to incorrect provisioning of functionality, an attacker can inject malicious payloads that execute within the context of the victim's browser session. This execution environment grants the payload elevated privileges compared to standard sandboxed web content, enabling it to read sensitive DOM properties or interact with other components on the page in ways intended to be prevented by the sanitizer rules.
The operational impact of this vulnerability is primarily centered around data exfiltration and potential privilege escalation within the browser's security model. A remote attacker can craft a malicious HTML page that exploits this flaw when loaded by an unsuspecting user who has previously visited or interacted with a vulnerable application utilizing the Sanitizer API improperly. By leveraging the crafted input, the attacker can extract sensitive information such as session cookies, personal identifiable information (PII), or internal application state data. This activity maps directly to the ATT&CK technique T1059 Command and Scripting Interpreter for executing malicious code within the browser context, and specifically relates to T1530 Data from Cloud Storage Object if the leaked data involves cloud-based resources accessed via API calls triggered by the exploit. The severity is classified as low because it typically requires user interaction or a specific sequence of events involving untrusted content processing, but even low-severity vulnerabilities can lead to significant security breaches when combined with other weaknesses in an application's architecture.
Mitigation strategies must focus on both immediate patching and long-term architectural improvements. Users should update Google Chrome to version 155.0.8059.39 or later immediately, as this release contains the corrected implementation of the Sanitizer API that properly enforces input validation rules. For developers integrating web technologies into their applications, it is critical to ensure that any use of the Sanitizer API follows best practices for configuring allowed tags and attributes strictly according to OWASP guidelines. Regular security audits should be conducted to verify that third-party libraries or custom implementations do not introduce similar flaws by misconfiguring sanitization rules. Additionally, implementing Content Security Policy (CSP) headers can provide an additional layer of defense by restricting the sources from which scripts and other resources are loaded, thereby reducing the impact if a vulnerability like this is exploited in the future. Continuous monitoring for anomalous DOM manipulation patterns and logging deviations in sanitizer behavior can also aid in early detection of such exploitation attempts.