CVE-2026-58704 Overview
CVE-2026-58704 is a permission bypass vulnerability in the Cellular Modem component of Google Android. A logic error in the modem code allows an attacker on an adjacent network to escalate privileges without user interaction and without any prior execution privileges. The flaw is tracked under CWE-285: Improper Authorization and is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Google addressed the issue in the Android Security Bulletin 2026-09-01.
Critical Impact
Attackers within radio proximity can bypass modem permission checks to achieve privilege escalation with full confidentiality, integrity, and availability impact — no user interaction required.
Affected Products
- Google Android (Pixel devices covered by the 2026-09-01 security patch level)
- Devices using the vulnerable Cellular Modem component
- Android builds prior to the 2026-09-01 security patch level
Discovery Timeline
- 2026-09-01 - Google releases security patch in the Pixel Security Bulletin
- 2026-09-15 - CVE-2026-58704 published to NVD
- 2026-09-17 - Last updated in NVD database
Technical Details for CVE-2026-58704
Vulnerability Analysis
The vulnerability resides in the Cellular Modem component of Android. A logic error in the code path that evaluates permission checks allows an attacker to bypass authorization enforcement. Because the modem processes radio-layer traffic before higher-level Android permission boundaries apply, the flaw exposes privileged modem functionality to unauthenticated peers on the same radio link. CISA has confirmed active exploitation by listing this CVE in the KEV catalog.
Root Cause
The root cause is an improper authorization defect classified as [CWE-285]. A control-flow decision in the modem firmware fails to correctly enforce the intended permission model. When specific message conditions are met, the code executes a privileged branch that should have been gated by an authorization check. This results in privilege escalation entirely within the modem boundary.
Attack Vector
The attack vector is Adjacent Network, meaning the attacker must be within radio range or otherwise able to reach the device over the cellular link — for example, through a rogue base station or a compromised network element. Exploitation requires no privileges and no user interaction. A successful attack yields high impact to confidentiality, integrity, and availability, consistent with modem-level control over device communications.
No public proof-of-concept code is available in the referenced sources. Refer to the Android Security Bulletin 2026-09-01 for vendor technical details.
Detection Methods for CVE-2026-58704
Indicators of Compromise
- Unexpected modem resets, crashes, or firmware restart events recorded in device logs
- Devices attaching to unfamiliar or unauthorized cell towers, including downgrade to 2G/3G networks
- Anomalous baseband command traffic or unexplained changes to modem configuration state
Detection Strategies
- Compare device build fingerprints and security patch levels across the fleet to identify systems missing the 2026-09-01 patch
- Correlate radio-layer telemetry with proximity-based anomalies such as rogue base station indicators
- Monitor mobile device management (MDM) inventory for Pixel and Android devices reporting outdated modem firmware
Monitoring Recommendations
- Enable enterprise MDM compliance rules that flag or quarantine devices below the 2026-09-01 security patch level
- Ingest Android device attestation and patch-level data into a centralized analytics platform for continuous review
- Track CISA KEV catalog updates and correlate against fleet inventory to prioritize remediation
How to Mitigate CVE-2026-58704
Immediate Actions Required
- Apply the Android 2026-09-01 security patch level to all affected devices without delay
- Prioritize patching for high-risk users, executives, and devices operating in untrusted radio environments
- Verify patch deployment through MDM reporting and device attestation
Patch Information
Google published the fix in the Android Security Bulletin 2026-09-01. Devices reporting a security patch level of 2026-09-01 or later contain the corrected Cellular Modem component. OEMs distributing Android builds must integrate the upstream fix and ship an updated firmware image; users should install the update through standard system update channels.
Workarounds
- Restrict device use in untrusted radio environments where rogue base stations may operate
- Disable 2G connectivity where supported by the device to reduce exposure to downgrade-based radio attacks
- Enforce MDM policies that block or isolate devices lacking the 2026-09-01 patch level from sensitive corporate resources
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
