CVE-2026-21049 Overview
CVE-2026-21049 is an out-of-bounds write vulnerability in the libpadm.so library shipped on Samsung mobile devices. The flaw exists in versions prior to the Samsung Maintenance Release (SMR) Jul-2026 Release 1. Local attackers can exploit the memory corruption condition to execute arbitrary code on affected devices. Samsung addressed the issue in its July 2026 security bulletin. The vulnerability requires local access with low privileges but no user interaction, making malicious applications on the device a viable attack path.
Critical Impact
Successful exploitation allows local attackers to execute arbitrary code within the context of the vulnerable library, compromising confidentiality and integrity on affected Samsung devices.
Affected Products
- Samsung mobile devices using libpadm.so prior to SMR Jul-2026 Release 1
- Samsung Android firmware builds released before the July 2026 security patch level
- Devices that have not applied the Samsung Mobile Security Maintenance Release for July 2026
Discovery Timeline
- 2026-07-10 - CVE-2026-21049 published to NVD
- 2026-07-11 - Last updated in NVD database
Technical Details for CVE-2026-21049
Vulnerability Analysis
The vulnerability is an out-of-bounds write in libpadm.so, a shared library present on Samsung mobile devices. Out-of-bounds write conditions occur when code writes data past the boundary of an allocated memory buffer. This class of memory corruption [CWE-787] can overwrite adjacent stack or heap structures, including function pointers, return addresses, or object metadata. Attackers who control the written data can pivot the corruption into arbitrary code execution. Because libpadm.so runs within the process context of applications that load it, exploitation grants the attacker the privileges of the calling process.
Root Cause
The root cause is insufficient bounds checking on data written to a buffer inside libpadm.so. Samsung has not published byte-level detail on the affected function. The advisory indicates the write operation occurs before length validation completes, permitting a controlled overwrite of adjacent memory. The fix is delivered as part of SMR Jul-2026 Release 1.
Attack Vector
The attack vector is local. An attacker must have code execution on the device, typically through a malicious or compromised Android application with permissions sufficient to invoke the vulnerable libpadm.so code path. No user interaction is required after the attacker's code runs. The exploit does not traverse the network, and no elevated privileges are required beyond those held by the calling process. See the Samsung Mobile Security Update for further vendor-provided context.
Detection Methods for CVE-2026-21049
Indicators of Compromise
- Unexpected crashes or SIGSEGV signals in processes that link against libpadm.so
- Installation of untrusted third-party applications requesting access to platform libraries
- Devices reporting a security patch level earlier than July 2026 while running production workloads
Detection Strategies
- Query mobile device management (MDM) inventories for Samsung devices reporting a patch level below 2026-07-01
- Correlate application install events with subsequent native crash reports referencing libpadm.so
- Review Android tombstone logs on managed devices for faulting library entries matching libpadm.so
Monitoring Recommendations
- Ingest MDM compliance telemetry into a centralized log platform to track patch adoption across the fleet
- Alert on newly sideloaded applications on Samsung devices in enterprise deployments
- Monitor Samsung's monthly security bulletins and map advisories to affected devices in your inventory
How to Mitigate CVE-2026-21049
Immediate Actions Required
- Apply Samsung Maintenance Release SMR Jul-2026 Release 1 to all affected Samsung mobile devices
- Enforce a minimum Android security patch level of 2026-07-01 through MDM compliance policies
- Restrict installation of untrusted applications through Google Play Protect and enterprise app allowlists
Patch Information
Samsung published the fix in the July 2026 Security Maintenance Release. Refer to the Samsung Mobile Security Update bulletin for device-specific firmware availability. Deploy the update through Samsung's over-the-air (OTA) mechanism or enterprise firmware management tooling.
Workarounds
- No vendor-supplied workaround is available; patching is the supported remediation
- Reduce risk by preventing installation of unverified applications until the patch is applied
- Disable or uninstall applications known to invoke libpadm.so code paths where feasible until devices are updated
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
