{"cve":"CVE-2026-42246","nvd":{"published":"2026-05-09T20:16:28.163","modified":"2026-08-24T13:18:41.420","status":"Modified","description":"Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAP#starttls to return \"successfully\", without starting TLS. This issue has been patched in versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","score":7.6},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","score":7.4},"cwes":["CWE-392","CWE-393","CWE-636","CWE-754","CWE-841","CWE-325"],"references":["https://github.com/ruby/net-imap/commit/0ede4c40b1523dfeaf95777b2678e54cc0fd9618","https://github.com/ruby/net-imap/commit/24a4e770b43230286a05aa2a9746cdbb3eb8485e","https://github.com/ruby/net-imap/commit/97e2488fb5401a1783bddd959dde007d9fbce42c","https://github.com/ruby/net-imap/commit/f79d35bf5833f186e81044c57c843eda30c873da","https://github.com/ruby/net-imap/releases/tag/v0.3.10"],"products":["ruby-lang:net\\"],"source":"nvd","synced_at":"2026-10-19T22:33:55.586217763+00:00"},"epss":{"cve":"CVE-2026-42246","score":0.00312,"percentile":0.24173,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-vcgp-9326-pqcp","url":"https://osv.dev/vulnerability/GHSA-vcgp-9326-pqcp","summary":"net-imap vulnerable to STARTTLS stripping via invalid response timing","modified":"2026-09-10T03:50:47.706717838Z","packages":[{"ecosystem":"RubyGems","name":"net-imap","purl":"pkg:gem/net-imap","ranges":[">=0.6.0 <0.6.4"],"fixed":["0.6.4"]},{"ecosystem":"RubyGems","name":"net-imap","purl":"pkg:gem/net-imap","ranges":[">=0.5.0 <0.5.14"],"fixed":["0.5.14"]},{"ecosystem":"RubyGems","name":"net-imap","purl":"pkg:gem/net-imap","ranges":[">=0.4.0 <0.4.24"],"fixed":["0.4.24"]},{"ecosystem":"RubyGems","name":"net-imap","purl":"pkg:gem/net-imap","ranges":["<0.3.10"],"fixed":["0.3.10"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}