CVE-2020-26301: 
JavaScript vulnerability analysis and mitigation

The CVE-2020-26301 vulnerability affects ssh2, a client and server module written in pure JavaScript for node.js. The vulnerability was discovered in versions before 1.4.0 and involves a command injection vulnerability that only exists on Windows systems. This security issue was fixed with the release of version 1.4.0 (GitHub Advisory).

The vulnerability is classified as a command injection flaw (CWE-78: Improper Neutralization of Special Elements used in an OS Command). It received a CVSS v3.1 base score of 10.0 CRITICAL from NIST NVD, while GitHub assessed it with a score of 7.5 HIGH. The vulnerability specifically affects the agent method in the ssh2 library when running on Windows systems (NVD).

If exploited, this vulnerability could lead to remote code execution if a client of the library calls the vulnerable method with untrusted input. The impact is particularly severe on Windows systems where attackers could potentially execute arbitrary commands (GitHub Advisory).

The vulnerability has been fixed in ssh2 version 1.4.0. Users are advised to upgrade to this version or later to mitigate the risk. The fix was implemented through a code rewrite, as documented in the patch commit (GitHub Patch).