CVE-2026-27648: OpenHarmony RCE Vulnerability

CVE-2026-27648 Overview

CVE-2026-27648 is an out-of-bounds write vulnerability [CWE-787] affecting OpenHarmony v6.0 and prior versions. A remote attacker holding low-level privileges can exploit the flaw to achieve arbitrary code execution within pre-installed applications. The vulnerability requires no user interaction and is reachable across the network, which broadens the attack surface significantly.

The issue was disclosed through the OpenHarmony security disclosure process. The CVSS 3.1 base score of 8.8 reflects the combined impact on confidentiality, integrity, and availability of affected devices running the open-source operating system.

Critical Impact

Remote attackers with low privileges can execute arbitrary code in pre-installed OpenHarmony apps, compromising device confidentiality, integrity, and availability.

Affected Products

• OpenHarmony v6.0
• OpenHarmony versions prior to v6.0
• Devices running pre-installed apps on the affected OpenHarmony releases

Discovery Timeline

• 2026-05-19 - CVE-2026-27648 published to NVD
• 2026-05-19 - Last updated in NVD database

Technical Details for CVE-2026-27648

Vulnerability Analysis

The vulnerability is classified as an out-of-bounds write [CWE-787]. Software writes data past the end, or before the beginning, of an allocated buffer. In OpenHarmony, the flawed routine operates within the execution context of pre-installed applications, which typically run with elevated trust on the device.

A successful write outside intended memory bounds corrupts adjacent structures. Attackers can leverage this corruption to redirect control flow and execute attacker-supplied instructions. Because the attack vector is network-based and requires only low privileges, an authenticated remote actor can trigger the flaw without local access.

The scope remains unchanged, meaning the impact is contained to the vulnerable component. However, that component handles pre-installed apps, so the practical effect includes full compromise of those applications and any data they process.

Root Cause

The root cause is missing or incorrect bounds checking on data written to a buffer inside an OpenHarmony component reachable by pre-installed apps. Specific affected functions are not disclosed in the public advisory. Refer to the OpenHarmony Security Disclosure for vendor-published technical details.

Attack Vector

The attacker sends crafted network input that reaches a pre-installed app interface on the OpenHarmony device. With low-privilege credentials already in place, the input drives a write past the allocated buffer boundary. No user interaction is required, and the attack completes at low complexity. The result is arbitrary code execution within the targeted pre-installed app context.

No public proof-of-concept exploit code is currently available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2026-27648

Indicators of Compromise

• Unexpected crashes, restarts, or memory faults in OpenHarmony pre-installed applications
• Anomalous outbound network connections originating from device application processes
• Unauthorized changes to files or configuration owned by pre-installed apps
• Newly spawned child processes from pre-installed app contexts that do not match baseline behavior

Detection Strategies

• Inspect network traffic destined for OpenHarmony device services for malformed or oversized payloads targeting application endpoints
• Correlate device logs for repeated low-privilege authentication followed by app process anomalies
• Hash and integrity-check pre-installed application binaries against known-good baselines
• Map observed behavior to MITRE ATT&CK techniques for Exploitation for Client Execution and Exploitation of Remote Services

Monitoring Recommendations

• Centralize OpenHarmony device telemetry, including crash dumps and application logs, for behavioral analysis
• Alert on memory corruption signatures, segmentation faults, and abnormal exit codes from pre-installed apps
• Monitor authenticated session activity for accounts with low privileges that interact with application services

How to Mitigate CVE-2026-27648

Immediate Actions Required

• Inventory all devices running OpenHarmony v6.0 or earlier and identify those exposed to untrusted networks
• Restrict network access to OpenHarmony device application interfaces using firewall rules or network segmentation
• Rotate and tighten credentials for any accounts that can authenticate to affected devices
• Apply vendor-provided patches as soon as they are published in the OpenHarmony security disclosure repository

Patch Information

Consult the OpenHarmony Security Disclosure for the authoritative list of fixed versions and patch commits. Upgrade affected devices to a release in which the out-of-bounds write has been remediated.

Workarounds

• Disable or remove pre-installed applications that are not required for device function
• Place affected devices behind network controls that block untrusted inbound traffic
• Enforce strict least-privilege policies so low-privilege accounts cannot reach vulnerable application interfaces

# Example: restrict inbound access to OpenHarmony device services
# Replace <device-ip> and <trusted-subnet> with environment values
iptables -A INPUT -s <trusted-subnet> -d <device-ip> -j ACCEPT
iptables -A INPUT -d <device-ip> -j DROP