CVE-2022-27810 in Hermes
Summary
by MITRE • 10/07/2022
It was possible to trigger an infinite recursion condition in the error handler when Hermes executed specific maliciously formed JavaScript. This condition was only possible to trigger in dev-mode (when asserts were enabled). This issue affects Hermes versions prior to v0.12.0.
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Analysis
by VulDB Data Team • 05/15/2026
The vulnerability identified as CVE-2022-27810 represents a critical flaw in the Hermes JavaScript engine used by Facebook's React Native framework. This issue manifests as an infinite recursion condition within the error handling mechanism when processing specifically crafted malicious JavaScript code. The vulnerability exists exclusively in development mode environments where assertions are enabled, making it particularly concerning for developers who may inadvertently expose this weakness during testing phases. The affected versions prior to v0.12.0 of Hermes demonstrate a fundamental design flaw in how the engine manages error conditions, creating a potential denial of service scenario that could disrupt application execution.
The technical root cause of this vulnerability stems from improper handling of error conditions within the Hermes JavaScript engine's internal error management system. When maliciously formed JavaScript code is executed in dev-mode with assertions enabled, the error handler enters a recursive loop that cannot be terminated naturally. This infinite recursion occurs because the error handling mechanism fails to properly break the recursive cycle when encountering specific patterns in the input JavaScript code. The vulnerability operates at the engine level rather than the application level, meaning it affects any React Native application using Hermes prior to version 0.12.0, regardless of the application's specific implementation. This characteristic places the vulnerability squarely within the domain of CWE-835, which addresses infinite loops or recursion conditions that can lead to system instability and denial of service.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to potentially compromise development environments and testing workflows. Since the issue only manifests in dev-mode with assertions enabled, it primarily affects developers working in development environments rather than production deployments. However, this creates a significant risk for development teams who may inadvertently expose this vulnerability during testing phases or when running debug builds. The vulnerability could be exploited by attackers to disrupt development processes, cause application crashes, or potentially gain insights into the internal workings of the JavaScript engine. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1499.004, which involves denial of service through resource exhaustion, though the specific implementation targets the error handling mechanism rather than network resources.
Mitigation strategies for CVE-2022-27810 focus primarily on upgrading to Hermes version 0.12.0 or later, which contains the necessary patches to resolve the infinite recursion issue in error handling. Development teams should immediately update their React Native dependencies to ensure they are using a patched version of the Hermes engine. Additionally, organizations should review their development workflows to minimize the exposure of development mode environments to untrusted inputs, as the vulnerability specifically requires assertions to be enabled. Security teams should implement monitoring for unusual error handling patterns in development environments and consider implementing input validation measures to prevent the execution of malicious JavaScript code even in development contexts. The vulnerability serves as a reminder of the importance of proper error handling design in runtime environments, particularly in JavaScript engines where error conditions can cascade into system instability.