Gist (< 6.1.0) contains improper certificate validation vulnerability
Published: June 16, 2026
SECURITY IDENTIFIERS
- CVE: CVE-2026-105221 (NVD)
- GHSA: GHSA-phqh-xp3p-h6mr
GEM
SEVERITY
CVSS v3.x: 7.4 (High)
UNAFFECTED VERSIONS
>= 2.0.0, < 4.0.0
PATCHED VERSIONS
>= 6.1.0
DESCRIPTION
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.
RELATED
- https://nvd.nist.gov/vuln/detail/CVE-2026-105221
- https://rubygems.org/gems/gist/versions/6.1.0
- https://github.com/defunkt/gist/compare/v6.0.0...v6.1.0
- https://github.com/defunkt/gist/pull/374
- https://github.com/defunkt/gist/issues/373
- https://github.com/defunkt/gist/commit/07ccc1a6d46e9d36f0e85d0b1c5d795890ae6bcf
- https://github.com/defunkt/gist/blob/v6.0.0/lib/gist.rb#L466-L468
- https://www.vulncheck.com/advisories/gist-rubygem-before-6.1.0-disabled-tls-certificate-verification
- https://github.com/github/advisory-database/pull/10408
- https://github.com/advisories/GHSA-phqh-xp3p-h6mr