CVE-2025-59419: Netty netty-codec-smtp SMTP Command Injection Vulnerability Allowing Email Forgery
Affected: netty · Exploitation: possible (1 to 10%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 75% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- netty · netty< 4.2.7.Final; >= 4.2.0.Alpha1, < 4.1.128.Final
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Possible (1 to 10%). EPSS between 1% and 10%.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- netty
- Published
- October 2025
CoverageNo articles yet
No CyberSIXT article names CVE-2025-59419 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.