CVE•Published 2026-05-09•Modified 2026-05-18•1 article on news•5 live references•NVD data
CVE-2026-42257Ruby-lang · Net\
Vulnerability data via NVD (ingested)
CVSS v3.1
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS percentile
—
Weaknesses (CWE)
Description
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.
Timeline
Published 2026-05-09
Modified 2026-05-18
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
Shodan · vuln tag0 hosts
vuln:CVE-2026-42257Hosts Shodan has explicitly fingerprinted as vulnerable.
Shodan · product + version
product:"Ruby-lang Net\" version:"\"Version-pinned fingerprint from NVD's first vulnerable CPE.
Shodan · banner/body mention
http.html:"Net\"HTTP body or banner mentions "Net\" — catches deploys Shodan didn't identify as a product.
More intel sources (5)
Shodan report
vuln:CVE-2026-42257Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-42257Censys host search filtered to this CVE id.
grep.app
CVE-2026-42257Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-42257GitHub code search for direct mentions.
Google dork
"CVE-2026-42257" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.
Known PoCs on GitHub
No public proof-of-concept repositories found for CVE-2026-42257 on GitHub.