CVE-2025-8881: Google Chrome Information Disclosure Flaw

CVE-2025-8881 Overview

CVE-2025-8881 is an inappropriate implementation flaw in the File Picker component of Google Chrome prior to version 139.0.7258.127. A remote attacker who convinces a user to perform specific UI gestures can leak cross-origin data through a crafted HTML page. The issue is categorized under [CWE-303] and affects Chrome on Windows, macOS, and Linux. Google classifies the Chromium severity as Medium, and the CVSS 3.1 base score is 6.5.

Critical Impact
Successful exploitation enables cross-origin information disclosure, breaking the same-origin policy boundary that isolates content between web origins.

Affected Products

Google Chrome versions prior to 139.0.7258.127
Chrome for Apple macOS, Microsoft Windows, and Linux desktop builds
Downstream Chromium-based browsers that inherit the File Picker implementation

Discovery Timeline

2025-08-13 - CVE-2025-8881 published to NVD
2025-08-12 - Google releases Chrome Stable Channel Update including the fix
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-8881

Vulnerability Analysis

The defect resides in Chrome's File Picker implementation, the browser subsystem that renders file selection dialogs when a page invokes <input type="file"> or the File System Access API. The implementation does not correctly enforce origin boundaries during user-driven interactions. An attacker who lures a victim to a crafted HTML page and induces specific mouse or keyboard gestures can cause the browser to expose data belonging to a different origin. The impact is limited to confidentiality, with no integrity or availability effect. User interaction is required, which lowers the practical exploitability but does not eliminate the risk in targeted phishing or social engineering campaigns.

Root Cause

The underlying weakness maps to [CWE-303], an incorrect implementation of an authentication or trust-boundary algorithm. In this case, the File Picker code path fails to validate that operations initiated within its UI remain scoped to the initiating origin. This gap allows a page under attacker control to observe content or metadata that should remain inaccessible under the same-origin policy.

Attack Vector

Exploitation is network-based and requires no privileges, but it depends on user interaction with the crafted page. A typical attack scenario involves an attacker hosting a malicious site, driving a victim to it through phishing or malvertising, and then using UI overlays, clickjacking-style layouts, or scripted prompts to guide the user through the required gestures. Once the gestures complete, the attacker's page reads cross-origin data returned by the File Picker flow. Refer to the Chromium Issue Tracker Entry for additional technical context once the bug is unrestricted.

Detection Methods for CVE-2025-8881

Indicators of Compromise

Browser telemetry showing Chrome versions earlier than 139.0.7258.127 still active on managed endpoints.
Outbound connections from user endpoints to newly registered domains that host pages invoking file picker prompts alongside cross-origin iframe content.
Web proxy logs recording repeated visits to pages that combine file input elements with scripted UI overlays.

Detection Strategies

Inventory installed Chrome and Chromium-derived browser versions using endpoint management tooling and flag any host below 139.0.7258.127.
Correlate browser process telemetry with network destinations to surface user sessions that render file picker dialogs on untrusted origins.
Hunt for phishing pages by matching URL patterns and HTML content that request file selection from unrelated contexts.

Monitoring Recommendations

Ingest browser version and patch state into a centralized log repository and alert on drift from the approved baseline.
Monitor Secure Web Gateway logs for user navigation to low-reputation domains that trigger file dialog events.
Track user reports of unexpected file picker prompts and treat them as potential social engineering indicators.

How to Mitigate CVE-2025-8881

Immediate Actions Required

Update Google Chrome to 139.0.7258.127 or later on Windows, macOS, and Linux endpoints.
Restart Chrome after the update to ensure the patched binaries are loaded across all user sessions.
Audit Chromium-based browsers such as Microsoft Edge, Brave, and Opera and apply their vendor updates that pull in the upstream fix.

Patch Information

Google addressed the vulnerability in the Chrome Stable Channel update released on August 12, 2025. Details are published in the Google Chrome Stable Update advisory. Enterprises using managed update channels should confirm that the 139.0.7258.127 build has propagated through their deployment rings.

Workarounds

Enforce automatic browser updates through group policy or MDM to remove reliance on user-initiated patching.
Restrict access to untrusted web categories through Secure Web Gateway policies until patching completes.
Educate users to close unexpected file selection dialogs and report pages that request file interactions without a clear business purpose.

bash

# Verify installed Chrome version on Linux and Windows endpoints
# Linux
google-chrome --version

# Windows (PowerShell)
(Get-Item "$Env:ProgramFiles\Google\Chrome\Application\chrome.exe").VersionInfo.ProductVersion

# macOS
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version