CVE-2026-92033: Firefox for Android Privilege Escalation

CVE-2026-92033 Overview

CVE-2026-92033 is a privilege escalation vulnerability affecting Mozilla Firefox for Android. The flaw enables an attacker to gain elevated privileges within the browser context, potentially bypassing security boundaries that separate web content from application-level resources. Mozilla addressed the issue in Firefox 156. The vulnerability is classified under CWE-269: Improper Privilege Management and requires user interaction to trigger. Exploitation occurs over the network, typically through malicious web content rendered by the affected browser. Mozilla published details in Mozilla Security Advisory MFSA-2026-90 and tracked remediation in Mozilla Bug Report #2047339.

Critical Impact
An attacker who convinces a user to visit crafted web content can escalate privileges within Firefox for Android, resulting in high impact to confidentiality, integrity, and availability.

Affected Products

Mozilla Firefox for Android (versions prior to 156)
Android platform installations relying on affected Firefox builds
Enterprise mobile deployments using Firefox for Android as the standard browser

Discovery Timeline

2026-09-15 - CVE-2026-92033 published to NVD
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-92033

Vulnerability Analysis

CVE-2026-92033 is a privilege escalation flaw in Firefox for Android mapped to [CWE-269: Improper Privilege Management]. The vulnerability allows a lower-privileged execution context, such as untrusted web content, to obtain permissions reserved for higher-privileged browser components. On mobile browsers, such escalations often translate to unauthorized access to device APIs, stored credentials, or inter-application data. Mozilla did not publish full exploitation mechanics in the public advisory, and no public proof-of-concept is currently available.

The issue affects only the Android build of Firefox. Desktop builds are not enumerated in the advisory. Firefox 156 contains the corrective code path that enforces the intended privilege boundary.

Root Cause

The root cause is improper privilege management within Firefox for Android. A code path failed to correctly validate or restrict the privilege level associated with an operation, allowing an attacker-controlled context to perform actions outside its intended sandbox. Refer to Mozilla Bug Report #2047339 for vendor-tracked technical detail.

Attack Vector

Exploitation requires an attacker to deliver crafted content to a vulnerable Firefox for Android instance and induce the user to interact with it. The attack vector is network-based, typically through a malicious website, an ad served in a legitimate site, or a phishing link. Successful exploitation can lead to code or actions being executed with elevated browser privileges. No authentication is required by the attacker.

No verified public exploit code is available. See the Mozilla Security Advisory MFSA-2026-90 for the vendor description.

Detection Methods for CVE-2026-92033

Indicators of Compromise

Firefox for Android installations reporting versions below 156 across managed mobile fleets.
Unexpected outbound connections from the Firefox process to previously unseen domains following user browsing sessions.
Anomalous access to Android content providers or intents originating from the Firefox package.

Detection Strategies

Inventory installed Firefox for Android versions using mobile device management (MDM) telemetry and flag any build prior to 156.
Correlate mobile browser telemetry with threat intelligence on domains known to deliver browser exploitation kits.
Alert on Firefox process behavior deviating from established baselines, particularly privilege-sensitive API calls.

Monitoring Recommendations

Ingest mobile browser and MDM logs into a centralized analytics platform to track Firefox version drift.
Monitor for user reports of unexpected permission prompts, redirects, or app behavior after visiting external links.
Review web proxy and DNS logs for connections to newly registered or low-reputation domains from mobile users.

How to Mitigate CVE-2026-92033

Immediate Actions Required

Update Firefox for Android to version 156 or later on all managed and personal devices.
Push the update through Google Play managed distribution or MDM policy to enforce rapid rollout.
Communicate the risk to end users and instruct them to avoid untrusted links until patched.

Patch Information

Mozilla fixed CVE-2026-92033 in Firefox 156. Users and administrators should upgrade to Firefox for Android 156 or later. Refer to Mozilla Security Advisory MFSA-2026-90 and Mozilla Bug Report #2047339 for release details.

Workarounds

Restrict use of Firefox for Android on managed devices until the update to version 156 is confirmed installed.
Enforce browser selection policy via MDM to route users to an alternate, up-to-date browser during the remediation window.
Apply network-level filtering to block access to known malicious infrastructure that could deliver exploitation attempts.

bash

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

# Expected output should show versionName=156 or higher