CVE-2026-105221

critical · 9.1

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.

9.1

CVSS

0.2%

EPSS (exploit prob.)

13th

EPSS percentile

2026-10-04

Published

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Weaknesses

CWE-295

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

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-105221