CVE-2026-105221
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.
Published Oct 4, 2026 · Updated Oct 8, 2026
The full analysis for this CVE is not ready yet, so this page shows the scores and scope from the public record. How CVEs are selected
Key Facts
Patch in the next maintenance window- CVE-2026-105221 is a critical-severity vulnerability (CVSS 9.1).
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
Scores
CVSS
9.1
EPSS (30-day exploit likelihood)
n/a
Exploit maturity
None known
ATLAS score
n/a
Outside the curated set
FAQ
Common Questions.
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.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
Is CVE-2026-105221 On Your Attack Surface?
Brandefense matches it against the products discovered on your perimeter and opens a finding the day a CVE like this is listed.
Request A Demo