CriticalCritical vulnerability

CVE-2026-105221 (CVSS 9.1)

NVD · officialPublished Oct 4, 2026Risk 50/100

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.

Technical details

CVSS

9.1

AV:NetworkAC:HighPR:NoneUI:None

Evidence and sources

This record is attributed to NVD. Exploitation status and remediation guidance are kept separate from the vulnerability's technical severity.

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