Vulnerability 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 Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ruby-Lang | Net\ | < 0.3.10, \ |
Related Weaknesses (CWE)
References
- https://github.com/ruby/net-imap/commit/0ede4c40b1523dfeaf95777b2678e54cc0fd9618Patch
- https://github.com/ruby/net-imap/commit/24a4e770b43230286a05aa2a9746cdbb3eb8485ePatch
- https://github.com/ruby/net-imap/commit/97e2488fb5401a1783bddd959dde007d9fbce42cPatch
- https://github.com/ruby/net-imap/commit/f79d35bf5833f186e81044c57c843eda30c873daPatch
- https://github.com/ruby/net-imap/releases/tag/v0.3.10Release Notes
- https://github.com/ruby/net-imap/releases/tag/v0.4.24Release Notes
- https://github.com/ruby/net-imap/releases/tag/v0.5.14Release Notes
- https://github.com/ruby/net-imap/security/advisories/GHSA-vcgp-9326-pqcpMitigationVendor Advisory
FAQ
What is CVE-2026-42246?
CVE-2026-42246 is a vulnerability with a CVSS score of 7.4 (HIGH). 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#starttl...
How severe is CVE-2026-42246?
CVE-2026-42246 has been rated HIGH with a CVSS base score of 7.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-42246?
Check the references section above for vendor advisories and patch information. Affected products include: Ruby-Lang Net\.