CVE-2026-11008: Chrome WebAppInstalls Cross-Origin Data Leak (CVSS 6.5)

Technical summary

CVE-2026-11008 is a CWE-20 (Improper Input Validation) vulnerability residing in the WebAppInstalls component of Google Chrome. The flaw stems from insufficient validation of untrusted input, which an attacker can exploit when the renderer process has already been compromised. A crafted HTML page serves as the attack vector, enabling unauthorized access to cross-origin data that would normally be protected by the browser's same-origin policy. The vulnerability affects Chrome versions prior to 149.0.7827.53.

Business impact

This vulnerability poses a data confidentiality risk in environments where Chrome is the primary browser. If an attacker successfully compromises the renderer process—often the first step in a multi-stage attack—this flaw provides an additional avenue to exfiltrate sensitive customer or employee data from web applications. Organizations relying on web-based SaaS platforms, cloud services, or internal web applications should treat this as part of a broader renderer-compromise scenario and prioritize isolation measures.

Affected systems

Google Chrome versions prior to 149.0.7827.53 on all supported operating systems (Windows, macOS, and Linux) are affected. The vulnerability is specific to Chrome; however, the underlying OS (Windows, macOS, or Linux) is listed as affected platforms and should be considered when assessing your fleet's patch status.

Exploitability

The vulnerability requires a pre-existing renderer process compromise, making it a secondary attack in a chain rather than a primary entry vector. However, once that condition is met, exploitation is straightforward: the attacker crafts an HTML page and the user's browser processes it, triggering the data leak. The CVSS vector (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N) reflects network-based delivery with low attack complexity and user interaction, but emphasizes high confidentiality impact. It is not currently listed on the CISA Known Exploited Vulnerabilities catalog.

Remediation

Update Google Chrome to version 149.0.7827.53 or later on all endpoints. Verify the update by checking Chrome's version in Settings > About > Chrome (auto-update should occur, but manual verification ensures compliance). For organizations with managed Chrome deployments via Active Directory or Mobile Device Management (MDM), ensure patch deployment policies are configured and tracked to completion. No workarounds exist for this vulnerability; patching is the required remediation.

Patch guidance

Deploy Chrome 149.0.7827.53 or later across your organization. Most Chrome installations auto-update, but corporate environments should verify deployment via endpoint management tools. If you manage Chrome policy via Google Admin Console or similar tools, confirm that auto-updates are enabled and monitor rollout progress. For air-gapped or restricted environments, download and distribute the offline installer from Google's official release channels and verify the release notes prior to deployment.

Detection guidance

Monitor Chrome version inventory using Mobile Device Management (MDM) solutions, endpoint detection and response (EDR) platforms, or custom asset inventory scripts. Look for instances still running versions prior to 149.0.7827.53. In addition, monitor for suspicious renderer process behavior or crashes followed by attempts to access cross-origin resources—though direct detection of this flaw's exploitation is difficult without application-level logging. Organizations using Chrome Enterprise can review the Version History report in Admin Console to identify non-compliant devices.

Why prioritize this

This vulnerability merits prompt patching despite its MEDIUM CVSS score because it extends the impact of a compromised renderer process—a condition that attackers actively pursue through browser exploits, social engineering, or malicious extensions. While not currently weaponized in the wild (KEV status: no), the flaw reduces the cost of a successful multi-stage attack. Organizations should prioritize this alongside other Chrome security updates in their regular patch cycles, particularly for endpoints handling sensitive web-based applications or user data.

Risk score, explained

The CVSS 3.1 score of 6.5 reflects a MEDIUM severity assessment. The score captures high confidentiality impact (C:H) against a background of low attack complexity and no privilege requirement. However, the score's limitation is its dependence on the renderer process already being compromised; it does not fully model the attacker's need to first breach that process. In context, this is a chaining vulnerability: moderate on its own, but dangerous in combination with other Chrome renderer exploits. Organizations with high-value web applications should weight this toward the higher end of medium priority.

Frequently asked questions