CVE-2026-42246

high

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.

References

https://github.com/ruby/net-imap/security/advisories/GHSA-vcgp-9326-pqcp

https://github.com/ruby/net-imap/releases/tag/v0.5.14

https://github.com/ruby/net-imap/releases/tag/v0.4.24

https://github.com/ruby/net-imap/releases/tag/v0.3.10

https://github.com/ruby/net-imap/commit/f79d35bf5833f186e81044c57c843eda30c873da

https://github.com/ruby/net-imap/commit/97e2488fb5401a1783bddd959dde007d9fbce42c

https://github.com/ruby/net-imap/commit/24a4e770b43230286a05aa2a9746cdbb3eb8485e

https://github.com/ruby/net-imap/commit/0ede4c40b1523dfeaf95777b2678e54cc0fd9618

Details

Source: Mitre, NVD

Published: 2026-05-09

Updated: 2026-05-18

Risk Information

CVSS v2

Base Score: 7.1

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 7.4

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

Severity: High

CVSS v4

Base Score: 7.6

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

Severity: High

EPSS

EPSS: 0.0005