CVE-2026-105221criticalCWE-295

CVE-2026-105221: critical vulnerability in defunkt gist

Gist RubyGem before 6.1.0 Disabled TLS Certificate Verification

Published · Updated

48Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 9.1epss 0.2%
from disclosure to weapon2 days
Published on NVDOct 4
1st PoC+2d
exploitation probability
0.2%top 93% of all CVEs
observed exploitation
nono source reports it
1 public exploit(s)
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/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Affected products
defunkt · gist
public PoCs found — 1
githubgithub.com/abraxas/cve-2026-105221-gist-tls★ 0
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
References
https://github.com/defunkt/gisthttps://github.com/defunkt/gist/blob/v6.0.0/lib/gist.rb#L466-L468https://github.com/defunkt/gist/commit/07ccc1a6d46e9d36f0e85d0b1c5d795890ae6bcfhttps://github.com/defunkt/gist/issues/373https://www.vulncheck.com/advisories/gist-rubygem-before-6.1.0-disabled-tls-certificate-verification