CVE-2025-5896 in taro
Summary
by MITRE • 06/10/2025
A vulnerability was found in tarojs taro up to 4.1.1. It has been declared as problematic. This vulnerability affects unknown code of the file taro/packages/css-to-react-native/src/index.js. The manipulation leads to inefficient regular expression complexity. The attack can be initiated remotely. Upgrading to version 4.1.2 is able to address this issue. The name of the patch is c2e321a8b6fc873427c466c69f41ed0b5e8814bf. It is recommended to upgrade the affected component.
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Analysis
by VulDB Data Team • 06/26/2026
The vulnerability in tarojs taro version 4.1.1 represents a critical security flaw classified as an inefficient regular expression complexity issue within the css-to-react-native package. This vulnerability exists in the file taro/packages/css-to-react-native/src/index.js and demonstrates a classic example of a regular expression denial of service (REDoS) attack vector. The flaw allows malicious actors to craft input strings that cause the regular expression engine to consume excessive computational resources through catastrophic backtracking, effectively creating a performance degradation that can escalate into a full denial of service condition.
The technical implementation of this vulnerability stems from poorly constructed regular expressions that exhibit exponential time complexity when processing specific input patterns. In the context of tarojs framework which translates css styles to react native compatible formats, an attacker could manipulate css input data to trigger these inefficient regex patterns during the style processing phase. The attack vector is particularly concerning as it can be initiated remotely through user-supplied css content or configuration parameters that get processed by the vulnerable component. This represents a typical scenario where untrusted input flows into regular expression evaluation without proper sanitization or input validation measures.
The operational impact of this vulnerability extends beyond simple performance degradation to potentially compromise system availability and resource utilization. When exploited, the inefficient regex complexity can cause the application to hang or consume excessive cpu cycles, making it vulnerable to resource exhaustion attacks that affect overall system stability. The vulnerability affects a core component of the taro framework's styling capabilities, meaning any application using css-to-react-native functionality is at risk regardless of the specific implementation details. This aligns with CWE-1321 which specifically addresses regular expression vulnerabilities and their potential for causing denial of service conditions.
From an attack perspective this vulnerability maps directly to several tactics in the ATT&CK framework including privilege escalation through resource exhaustion and denial of service attacks. The remote exploitation capability means that attackers do not require local system access or elevated privileges, making the vulnerability particularly dangerous in web-facing applications. The patch addressing this issue involves a specific commit c2e321a8b6fc873427c466c69f41ed0b5e8814bf that likely refactors the problematic regular expressions to use more efficient patterns or implements input validation to prevent catastrophic backtracking scenarios.
Organizations utilizing tarojs taro versions prior to 4.1.2 should immediately prioritize upgrading their installations to mitigate this vulnerability. The recommended mitigation strategy involves not only applying the specific patch but also implementing broader input validation practices for any css processing components within applications. Security teams should monitor for potential exploitation attempts through log analysis and implement rate limiting or input sanitization measures as additional defensive controls. This vulnerability serves as a reminder of the critical importance of regular security updates and proper input validation in preventing denial of service attacks that can compromise application availability and user experience.
The broader implications of this vulnerability extend to software supply chain security considerations, as it demonstrates how seemingly innocuous components within development frameworks can contain critical security flaws. The affected component's role in translating css styles makes it particularly susceptible to attack through user input manipulation, highlighting the need for comprehensive security testing throughout the software development lifecycle. This case emphasizes the importance of using automated security scanning tools and maintaining up-to-date dependencies to prevent exploitation of known vulnerabilities that may not be immediately apparent during initial development phases.