CVE-2026-16373: Firefox Android Information Disclosure

CVE-2026-16373 Overview

CVE-2026-16373 is an information disclosure vulnerability in the Privacy component of Firefox for Android. Mozilla addressed the issue in Firefox 153. The flaw is classified under [CWE-200] (Exposure of Sensitive Information to an Unauthorized Actor) and can be triggered remotely over the network without user interaction or authentication. Mozilla documented the issue in Mozilla Security Advisory MFSA 2026-68 and Mozilla Bug Report #2021964.

Critical Impact
Remote attackers can obtain sensitive information handled by the Privacy component in Firefox for Android without requiring authentication or user interaction.

Affected Products

Mozilla Firefox for Android (versions prior to 153)
Privacy component within Firefox for Android
Firefox for Android mobile browser installations on affected releases

Discovery Timeline

2026-07-21 - CVE-2026-16373 published to NVD
2026-07-22 - Last updated in NVD database

Technical Details for CVE-2026-16373

Vulnerability Analysis

CVE-2026-16373 affects the Privacy component of Firefox for Android. The advisory categorizes the issue as information disclosure, meaning data intended to remain confidential can be observed by an unauthorized party. The confidentiality impact is high, while integrity and availability are not affected.

The issue is network-reachable and requires no privileges or user interaction. That combination means a remote actor hosting attacker-controlled content can trigger the disclosure when a user's browser processes it. Mozilla resolved the vulnerability in Firefox 153.

The EPSS probability is 0.29%, reflecting a low near-term exploitation forecast, but the impact profile still warrants prompt patching on mobile fleets where Firefox is deployed.

Root Cause

Mozilla's advisory attributes the flaw to the Privacy component in Firefox for Android and classifies it under [CWE-200]. Specific implementation details are limited in public sources. Refer to Mozilla Bug Report #2021964 for engineering-level context on the underlying defect and the corresponding fix.

Attack Vector

The attack vector is network-based. An attacker can deliver crafted web content or interact with the affected component remotely to elicit disclosure of sensitive data managed by the browser. Because the vulnerability requires no privileges and no user interaction beyond normal browsing, standard drive-by scenarios apply. No public proof-of-concept exploit is currently available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

No verified exploit code is available. See the referenced Mozilla advisory and bug report for authoritative technical detail.

Detection Methods for CVE-2026-16373

Indicators of Compromise

Firefox for Android instances running versions prior to 153 remain vulnerable and should be treated as at-risk assets.
Outbound connections from mobile browsers to unfamiliar domains immediately after page loads containing untrusted content.
Anomalous data egress patterns from mobile endpoints correlated with Firefox browser activity.

Detection Strategies

Inventory managed Android devices and identify Firefox installations at versions below 153 using mobile device management (MDM) telemetry.
Correlate browser version data with network telemetry to spot devices that have visited high-risk domains prior to patching.
Review web proxy and DNS logs for connections to domains hosting content designed to interact with the Privacy component.

Monitoring Recommendations

Continuously monitor Firefox version compliance across Android endpoints through MDM or unified endpoint management reporting.
Track new Mozilla security advisories and subscribe to updates from Mozilla Security Advisories.
Log and alert on mobile browser crash telemetry that may indicate exploitation attempts against browser components.

How to Mitigate CVE-2026-16373

Immediate Actions Required

Update Firefox for Android to version 153 or later on all managed and personal devices.
Push the updated Firefox package to enrolled Android endpoints through your MDM or enterprise app distribution channel.
Communicate patch guidance to end users who install Firefox for Android outside of managed channels.

Patch Information

Mozilla fixed CVE-2026-16373 in Firefox 153. Details are published in Mozilla Security Advisory MFSA 2026-68 with engineering context in Mozilla Bug Report #2021964. Users should install the update through Google Play, Mozilla's distribution channels, or enterprise app repositories.

Workarounds

Restrict use of Firefox for Android on managed devices until the update to version 153 has been confirmed.
Enforce mobile web filtering to block access to untrusted or unclassified web content from vulnerable browser versions.
Advise users to use an alternate updated browser on Android until the Firefox 153 update is applied.

bash

# Verify installed Firefox version on an Android device via ADB
adb shell dumpsys package org.mozilla.firefox | grep versionName