CVE-2026-42246
Published: May 20, 2026Last modified: May 21, 2026
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.4 |
| Attack Vector | NETWORK |
| Attack complexity | HIGH |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 25 LTS | ruby-net-imap | Fixed (0.5.14-r0) |
| Stream | ruby-net-imap | Fixed (0.5.14-r0) |
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
- https://github.com/ruby/net-imap/releases/tag/v0.4.24
- https://github.com/ruby/net-imap/releases/tag/v0.5.14
- https://github.com/ruby/net-imap/security/advisories/GHSA-vcgp-9326-pqcp