CVE-2026-16083 in PicoClaw
Summary
by MITRE • 07/18/2026
A security flaw has been discovered in Sipeed PicoClaw up to 0.2.9. This affects the function webhook.ParseRequest of the file pkg/channels/line/line.go of the component LINE Webhook. The manipulation results in authentication bypass by capture-replay. The attack may be launched remotely. The exploit has been released to the public and may be used for attacks. The reported GitHub issue was closed automatically with the label "not planned" by a bot.
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Analysis
by VulDB Data Team • 07/18/2026
The security vulnerability identified in Sipeed PicoClaw version 0.2.9 represents a critical authentication bypass flaw within the LINE Webhook component that could enable remote attackers to execute unauthorized operations. This vulnerability specifically resides in the webhook.ParseRequest function located in pkg/channels/line/line.go, where insufficient validation mechanisms allow malicious actors to manipulate request parameters and circumvent the intended authentication controls. The flaw directly enables capture-replay attacks, where attackers can intercept legitimate webhook requests and replay them to gain unauthorized access to the system's functionality.
The technical implementation of this vulnerability stems from inadequate input sanitization and validation within the ParseRequest function, which fails to properly verify the authenticity and integrity of incoming webhook payloads. This weakness creates a pathway for attackers to forge valid-looking requests that bypass authentication mechanisms entirely, effectively allowing them to impersonate legitimate users or systems. The vulnerability's remote exploitability means that attackers do not require physical access to the system, making it particularly dangerous as it can be targeted from anywhere on the internet.
The operational impact of this vulnerability extends beyond simple unauthorized access, potentially enabling complete compromise of the LINE webhook integration functionality within Sipeed PicoClaw. Attackers could leverage this flaw to send malicious messages, execute commands through the webhook interface, or gain persistent access to the system's communication channels. The closed GitHub issue with "not planned" label suggests that the maintainers have not prioritized addressing this security concern, leaving users exposed to potential exploitation.
Security professionals should consider this vulnerability in the context of CWE-287 which addresses improper authentication issues, and ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting. The lack of proper replay protection mechanisms makes this system particularly susceptible to man-in-the-middle attacks where captured tokens or signatures can be reused against the vulnerable service. Organizations using Sipeed PicoClaw should immediately implement network-level controls such as IP whitelisting, request rate limiting, and additional authentication layers to mitigate potential exploitation attempts.
Mitigation strategies must include immediate patching of the affected component if available, implementing proper request signature validation, and deploying comprehensive monitoring for suspicious webhook activity. The vulnerability's public exploit availability increases the urgency for remediation, as attackers can readily leverage existing tools to target systems running vulnerable versions. Network segmentation and strict firewall rules should be implemented to limit the attack surface, while security teams must establish incident response procedures specifically addressing webhook-based authentication bypass scenarios. Regular security assessments should include verification of webhook endpoint integrity and proper implementation of replay protection mechanisms to prevent similar vulnerabilities from emerging in the future.
The vulnerability demonstrates a classic example of insufficient authentication controls in webhook processing systems, where the assumption that incoming requests are legitimate leads to critical security gaps. The combination of remote exploitability, public availability of exploitation tools, and the lack of vendor response creates an environment where organizations must take proactive defensive measures to protect their systems from potential compromise through this authentication bypass mechanism.