CVE-2026-27781 Overview
CVE-2026-27781 affects OpenHarmony v6.0 and prior versions. The vulnerability allows a local attacker to trigger a denial of service (DoS) condition through an integer overflow weakness classified as [CWE-190]. Exploitation requires local access and low privileges, with no user interaction needed. The flaw impacts only availability, with no confidentiality or integrity consequences. OpenHarmony published the security disclosure detailing the issue in April 2026.
Critical Impact
A local, low-privileged attacker can crash or disrupt an affected OpenHarmony component by triggering an integer overflow, resulting in a denial of service on the local device.
Affected Products
- OpenHarmony v6.0
- OpenHarmony versions prior to v6.0
Discovery Timeline
- 2026-05-19 - CVE CVE-2026-27781 published to NVD
- 2026-05-19 - Last updated in NVD database
Technical Details for CVE-2026-27781
Vulnerability Analysis
CVE-2026-27781 is an integer overflow vulnerability in OpenHarmony, the open-source distributed operating system maintained by the OpenAtom Foundation. The weakness falls under [CWE-190], where an arithmetic operation produces a value that exceeds the storage capacity of the destination integer type. When the overflow occurs, subsequent logic relying on the corrupted value can cause unexpected behavior in a system component, resulting in a denial of service.
The vulnerability is exploitable only from a local context. An attacker must already possess low-privilege access on the device to send crafted inputs that trigger the overflow. The impact is restricted to availability, meaning the attacker cannot read protected data or modify system state through this flaw alone.
Root Cause
The root cause is improper validation of arithmetic operations on integer values inside an OpenHarmony component. Without proper bounds checking, attacker-influenced values can wrap around or exceed the storage size of the target variable. The resulting value drives downstream code into an invalid state, terminating the affected service or process.
Attack Vector
The attack vector is local. A user or process with low privileges on the device can supply input that reaches the vulnerable arithmetic path. Successful exploitation produces a denial of service against the affected OpenHarmony component, disrupting normal device operation until the service is restarted. Refer to the OpenHarmony Security Disclosure for component-specific technical details.
Detection Methods for CVE-2026-27781
Indicators of Compromise
- Unexpected termination or repeated restarts of OpenHarmony system services on affected devices.
- Crash logs or kernel messages referencing arithmetic faults, abort signals, or invalid memory operations.
- Local processes belonging to low-privilege users submitting unusually large or malformed numeric inputs to system interfaces.
Detection Strategies
- Monitor OpenHarmony device logs for service crash patterns correlated with specific local user activity.
- Inspect inter-process communication payloads for out-of-range numeric parameters delivered to vulnerable components.
- Compare runtime stability metrics against baseline behavior to identify availability anomalies introduced by exploit attempts.
Monitoring Recommendations
- Centralize OpenHarmony device logs in a log management or SIEM platform for correlation across the fleet.
- Alert on repeated abnormal terminations of the same service from the same local user context.
- Track patch deployment status across all OpenHarmony devices to confirm vulnerable versions are remediated.
How to Mitigate CVE-2026-27781
Immediate Actions Required
- Inventory all devices running OpenHarmony v6.0 or earlier and flag them for remediation.
- Apply the official OpenHarmony security update referenced in the vendor disclosure as soon as it is available for your build.
- Restrict local access on affected devices to trusted users and processes only.
Patch Information
OpenHarmony has documented the issue in its security disclosure repository. Refer to the OpenHarmony Security Disclosure for 2026-04 for the affected component, fixed version, and patch commit details. Upgrade affected devices to the patched OpenHarmony release that addresses CVE-2026-27781.
Workarounds
- Limit local account creation and reduce the number of low-privileged users on affected OpenHarmony devices.
- Disable or restrict access to the vulnerable component on devices that cannot be patched immediately, where operationally feasible.
- Implement device-level monitoring to detect and automatically restart impacted services to minimize downtime until patching is complete.
# Configuration example
# Verify OpenHarmony version on the device
param get const.ohos.version.release
# After patch deployment, confirm the updated build identifier
param get const.ohos.buildversion
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
