CVE-2026-55365 Overview
CVE-2026-55365 is an out-of-bounds write vulnerability affecting multiple functions in remap.c. The flaw stems from an incorrect bounds check that allows a local attacker with high privileges to write outside allocated memory. Successful exploitation results in local privilege escalation with System-level execution rights. User interaction is not required for exploitation. The issue is documented in the Android Security Bulletin for September 2026 and is classified under [CWE-787] Out-of-Bounds Write.
Critical Impact
A local attacker with elevated privileges can achieve System-level code execution on the target device without any user interaction, compromising confidentiality, integrity, and availability.
Affected Products
- Android platform components referenced in the September 2026 Pixel Security Bulletin
- Devices incorporating the vulnerable remap.c implementation
- Pixel devices covered by the September 2026 security patch level
Discovery Timeline
- 2026-09-15 - CVE-2026-55365 published to the National Vulnerability Database (NVD)
- 2026-09-16 - Last updated in the NVD database
Technical Details for CVE-2026-55365
Vulnerability Analysis
The vulnerability resides in multiple functions within remap.c, a source file associated with memory remapping operations. An incorrect bounds check permits write operations that extend beyond the intended memory region. Out-of-bounds writes of this nature typically corrupt adjacent memory structures, function pointers, or metadata used by the kernel or a privileged service. When leveraged carefully, this corruption can redirect control flow to attacker-controlled code executing with System privileges. The attack requires local access and elevated privileges, but no user interaction is needed once the attacker can invoke the vulnerable code path.
Root Cause
The root cause is an incorrect bounds check ([CWE-787]) in remap.c. The validation logic fails to properly constrain input sizes or offsets before performing a memory write, allowing writes past the end of the allocated buffer.
Attack Vector
A local attacker with high privileges invokes the vulnerable functions in remap.c with crafted parameters that bypass the flawed bounds check. The resulting out-of-bounds write corrupts memory belonging to a higher-privileged context, enabling privilege escalation to System. Because exploitation is entirely local and requires no user interaction, malicious applications already present on the device can chain this flaw with lower-privilege footholds to achieve full compromise.
No verified public proof-of-concept code is available. Refer to the Android Security Bulletin September 2026 for authoritative technical details.
Detection Methods for CVE-2026-55365
Indicators of Compromise
- Unexpected crashes or kernel oops messages referencing remap.c or related memory management routines
- Processes transitioning to System UID without a legitimate elevation path
- Installation or execution of applications that request unusual low-level memory operations
Detection Strategies
- Monitor Android device logs for repeated segmentation faults or SELinux denials involving privileged services
- Correlate application installation events with subsequent privilege-elevation activity on managed mobile fleets
- Compare device patch levels against the September 2026 Android Security Bulletin baseline to identify unpatched endpoints
Monitoring Recommendations
- Ingest mobile device management (MDM) telemetry to track patch-level compliance across the Android estate
- Alert on installation of applications from untrusted sources on devices below the September 2026 patch level
- Review crash reports and bug reports for anomalies in memory management components
How to Mitigate CVE-2026-55365
Immediate Actions Required
- Apply the September 2026 Android security patch level or later to all affected devices
- Inventory Android endpoints and prioritize patching for devices used by privileged users
- Restrict installation of applications from unknown sources through MDM policy enforcement
Patch Information
Google addressed CVE-2026-55365 in the September 2026 Android Security Bulletin. Devices must be updated to the 2026-09-01 security patch level or later. See the Android Security Bulletin September 2026 for the authoritative fix reference.
Workarounds
- Enforce Google Play Protect and block sideloading on managed devices until patches are deployed
- Limit device use to trusted applications and remove any application that requests unnecessary system-level access
- Retire or isolate devices that no longer receive security updates from the vendor
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
