Vulnerability in Ruby Net-imap
CVE-2026-42246
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 sta…
EPSS: 0.000 (3.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Ruby Net-imap — versions < 0.3.10, >= 0.4.0, < 0.4.24, >= 0.5.0, < 0.5.14
- Ruby-lang Net\ — versions \
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-42246?
- CVE-2026-42246 is a high-severity vulnerability in Ruby Net-imap, classified under CWE-392. CVSS score: 7.4/10. Published 2026-05-09.
- How severe is CVE-2026-42246?
- High severity. CVSS v3 base score is 7.4 out of 10.