Riskcovery

CVE-2026-42246

net-imap vulnerable to STARTTLS stripping via invalid response timing

State
Published
Severity
7.6 High
Published
May 9, 2026
Updated
Aug 24, 2026
Reserved
Apr 25, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
4.07.6 HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NGitHub_M
3.17.4 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Nredhat-SADP

Weaknesses

  • CWE-392 Missing Report of Error Condition
  • CWE-393 Return of Wrong Status Code
  • CWE-754 Improper Check for Unusual or Exceptional Conditions
  • CWE-636 Not Failing Securely ('Failing Open')
  • CWE-841 Improper Enforcement of Behavioral Workflow
  • CWE-325 Missing Cryptographic Step

Affected Products

ProductVersions
net-imapruby
  • < 0.3.10Affected
  • >= 0.4.0, < 0.4.24Affected
  • >= 0.5.0, < 0.5.14Affected
  • >= 0.6.0, < 0.6.4Affected

References

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