CVE-2026-31862 is an OS command injection vulnerability identified in the siteboon Cloud CLI product, known as claudecodeui, which serves as a desktop and mobile user interface for interacting with Claude Code, Cursor CLI, Codex, and Gemini-CLI. The vulnerability exists in versions prior to 1.24.0, where multiple Git-related API endpoints improperly handle user input parameters such as file names, branch names, commit messages, and commit identifiers. These parameters are passed to the execAsync() function using string interpolation without proper sanitization or neutralization of special characters. This unsafe coding practice allows an authenticated attacker to inject arbitrary operating system commands, which the application then executes with the privileges of the running process. The vulnerability is classified under CWE-78 (Improper Neutralization of Special Elements used in an OS Command), indicating a classic command injection flaw. The CVSS v3.1 base score is 9.1, with vector AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H, meaning the attack can be performed remotely over the network with low complexity, requires high-level privileges (authenticated user), no user interaction, and results in a complete compromise of confidentiality, integrity, and availability. The vulnerability affects all versions before 1.24.0 and has been addressed in the 1.24.0 release. Although no known exploits have been reported in the wild yet, the critical nature and ease of exploitation for authenticated users make this a high-risk issue for organizations using the affected software. The flaw could be leveraged to execute arbitrary commands, potentially leading to full system compromise, data exfiltration, or disruption of services.

The impact of CVE-2026-31862 is severe for organizations using the affected versions of siteboon's claudecodeui. Successful exploitation allows authenticated attackers to execute arbitrary OS commands, which can lead to full system compromise. This includes unauthorized access to sensitive data (confidentiality breach), modification or deletion of data (integrity breach), and disruption or denial of service (availability breach). Given the integration of claudecodeui with multiple developer tools and CLIs, attackers could pivot to other internal systems, escalate privileges, or implant persistent backdoors. The vulnerability's exploitation could severely disrupt software development workflows, compromise intellectual property, and damage organizational reputation. The requirement for authentication limits exposure to some extent, but insider threats or compromised credentials could still enable attacks. The lack of user interaction needed and the low attack complexity increase the risk of exploitation in environments where the software is deployed. Organizations relying on this tool for development or automation should consider the vulnerability critical and prioritize remediation to prevent potential breaches and operational impacts.

To mitigate CVE-2026-31862, organizations should immediately upgrade claudecodeui to version 1.24.0 or later, where the vulnerability is fixed. Until the upgrade can be applied, restrict access to the affected API endpoints by enforcing strict authentication and authorization controls, limiting usage to trusted users only. Implement network segmentation and firewall rules to reduce exposure of the affected services. Conduct thorough credential audits and enforce strong authentication mechanisms such as multi-factor authentication to reduce the risk of credential compromise. Review and monitor logs for suspicious command execution or anomalous API usage patterns indicative of exploitation attempts. Developers should audit any custom integrations or scripts that interact with the vulnerable endpoints to ensure they do not introduce similar injection risks. Additionally, consider deploying runtime application self-protection (RASP) or endpoint detection and response (EDR) solutions capable of detecting and blocking command injection attempts. Finally, educate developers and administrators about secure coding practices, especially regarding the handling of user input in command execution contexts.