cve.bz

CVE-2026-42257

5.8 mediumEPSS 0.4%

Medium (5.8) in ruby-lang net\. EPSS 0.4% chance of exploitation in the next 30 days. Fixed in net-imap 0.4.24, 0.5.14, 0.6.4.

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, several Net::IMAP commands accept a raw string argument that is sent to the server without validation or escaping. If this string is derived from user-controlled input, it may contain contain CRLF sequences, which an attacker can use to inject arbitrary IMAP commands. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.

Severity

CVSS 4.0

5.8 medium
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N

CVSS 3.1

9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.4% chance of exploitation in the next 30 days; higher than 37% of CVEs (scores of 2026-10-31)
CWEs
CWE-77, CWE-93
Published
Modified
Record from
the NVD, synced

Affected

Packages (OSV)

AdvisoryEcosystemPackageAffectedFixed in
GHSA-hm49-wcqc-g2xgRubyGemsnet-imap>=0.6.0 <0.6.40.6.4
GHSA-hm49-wcqc-g2xgRubyGemsnet-imap>=0.5.0 <0.5.140.5.14
GHSA-hm49-wcqc-g2xgRubyGemsnet-imap<0.4.240.4.24

References

Check your stackJSON