{"cve":"CVE-2025-59419","nvd":{"published":"2025-10-15T16:15:35.290","modified":"2026-10-19T16:10:00.260","status":"Deferred","description":"Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.128.Final and 4.2.7.Final, the SMTP codec in Netty contains an SMTP command injection vulnerability due to insufficient input validation for Carriage Return (\\r) and Line Feed (\\n) characters in user-supplied parameters. The vulnerability exists in io.netty.handler.codec.smtp.DefaultSmtpRequest, where parameters are directly concatenated into the SMTP command string without sanitization. When methods such as SmtpRequests.rcpt(recipient) are called with a malicious string containing CRLF sequences, attackers can inject arbitrary SMTP commands. Because the injected commands are sent from the server's trusted IP address, resulting emails will likely pass SPF and DKIM authentication checks, making them appear legitimate. This allows remote attackers who can control SMTP command parameters (such as email recipients) to forge arbitrary emails from the trusted server, potentially impersonating executives and forging high-stakes corporate communications. This issue has been patched in versions 4.1.129.Final and 4.2.8.Final. No known workarounds exist.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P","score":5.5},"cvss_v3":null,"cwes":["CWE-93"],"references":["https://github.com/netty/netty/commit/1782e8c2060a244c4d4e6f9d9112d5517ca05120","https://github.com/netty/netty/security/advisories/GHSA-jq43-27x9-3v86","https://www.depthfirst.com/post/our-ai-agent-found-a-netty-zero-day-that-bypasses-email-authentication-the-story-of-cve-2025-59419"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:12:35.277909958+00:00"},"epss":{"cve":"CVE-2025-59419","score":0.01553,"percentile":0.74954,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-jq43-27x9-3v86","url":"https://osv.dev/vulnerability/GHSA-jq43-27x9-3v86","summary":"Netty has SMTP Command Injection Vulnerability that Allows Email Forgery","modified":"2026-09-10T03:50:29.967090066Z","packages":[{"ecosystem":"Maven","name":"io.netty:netty-codec-smtp","purl":"pkg:maven/io.netty/netty-codec-smtp","ranges":[">=4.2.0.Alpha1 <4.2.7.Final"],"fixed":["4.2.7.Final"]},{"ecosystem":"Maven","name":"io.netty:netty-codec-smtp","purl":"pkg:maven/io.netty/netty-codec-smtp","ranges":["<4.1.128.Final"],"fixed":["4.1.128.Final"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}