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. 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.

CVSS 4.0

9.1CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 13% of CVEs (scores of 2026-10-25)

CWE

CWE-295

Published

2026-10-04

Modified

2026-10-06

Record from

the NVD, synced 2026-10-19

References

• 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
• https://github.com/defunkt/gist/issues/373
• https://www.vulncheck.com/advisories/gist-rubygem-before-6.1.0-disabled-tls-certificate-verification

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