CVE-2026-105221: gist: gist: Traffic interception and credential theft via improper TLS certificate validation

Severity: Critical

CVSS Score: 7.4

The gist RubyGem before 6.1.0 contains an improper certificate validation vulnerability that allows on-path attackers to intercept HTTPS traffic because http_connection in lib/gist.rb sets VERIFY_NONE. Attackers can present any certificate to read or modify GitHub API traffic, stealing OAuth tokens and login credentials to read and modify the victim's gists.