Gist RubyGem before 6.1.0 Disabled TLS Certificate Verification

Advisories

Gist RubyGem before 6.1.0 Disabled TLS Certificate Verification

severity: critical
date: 10/4/2026
Affecting: gist >= 4.0.0, < 6.1.0
CVE: CVE-2026-105221
CWE: CWE-295 Improper Certificate Validation
CVSS: 9.1
CVSS V4 Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
References: GitHub Issue #373
https://github.com/defunkt/gist
https://github.com/defunkt/gist/blob/v6.0.0/lib/gist.rb#L466-L468
https://github.com/defunkt/gist/commit/07ccc1a6d46e9d36f0e85d0b1c5d795890ae6bcf
Credit: Siyang Wu
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.

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