CVE-2021-37860: Cross-site Scripting in Mattermost

The provided information describes an XSS vulnerability due to insufficient sanitization of clipboard contents when CSP is disabled. However, the GitHub patch and commit diff details are explicitly marked as unavailable, and neither the CVE description nor the advisory provides specific function names or code locations. While the vulnerability likely exists in clipboard input handling or HTML rendering logic, the lack of technical implementation details makes it impossible to identify specific vulnerable functions with high confidence. Mattermost's server-side Go code would require analysis of how clipboard data is processed and sanitized in versions <5.39.0 to pinpoint exact functions, which isn't provided in the available data.