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Fencer Vulns
medium 5.5

CVE-2025-59419 json

Netty netty-codec-smtp SMTP Command Injection Vulnerability Allowing Email Forgery

published 2025-10-15 12 mo ago modified 2026-10-19 20 d ago also EUVD-2025-34685 , GHSA-jq43-27x9-3v86

cvss
5.5
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven io.netty:netty-codec-smtp 4.1.128.Final, 4.2.7.Final
  • io.netty.codec-smtp netty-codec-smtp 4.1.128.Final, 4.2.7.Final
  • io.netty netty-codec-smtp 4.1.128.Final, 4.2.7.Final
  • netty netty-codec-smtp 4.1.128.Final, 4.2.7.Final
  • netty_project netty-codec-smtp 4.1.128.Final, 4.2.7.Final
  • netty Debian 12 1:4.1.48-7+deb12u2
  • netty Debian 13 1:4.1.48-10+deb13u1
  • netty Debian 14 1:4.1.48-11

debian advisories DEBIAN-CVE-2025-59419

  • netty Ubuntu 25.10 1:4.1.48-10ubuntu0.25.10.1
  • netty Ubuntu Pro 18.04 LTS 1:4.1.7-4ubuntu0.1+esm4
  • netty Ubuntu Pro 20.04 LTS 1:4.1.45-1ubuntu0.1~esm3
  • netty Ubuntu Pro 22.04 LTS 1:4.1.48-4+deb11u2ubuntu0.1~esm2
  • netty Ubuntu Pro 24.04 LTS 1:4.1.48-9ubuntu0.1~esm2

ubuntu advisories UBUNTU-CVE-2025-59419

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • netty-tcnative SLE Module for Development Tools 15 SP7, SLE Module for Development Tools 15 SP6, openSUSE Leap 15.6 2.0.74-150200.3.33.1
  • netty SLE Module for Package Hub 15 SP7, SLE Module for Package Hub 15 SP6, openSUSE Leap 15.6 4.1.128-150200.4.37.1

suse advisories SUSE-SU-2025:4087-1

  • netty openSUSE Tumbleweed 4.1.128-1.1

opensuse advisories openSUSE-SU-2025:15667-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-59419 updated cvss 5.3

io.netty/netty-codec-smtp: Netty netty-codec-smtp SMTP Command Injection

  • Red Hat Logging Subsystem for Red Hat OpenShift netty-codec-smtp Red Hat AMQ Clients netty-codec-smtp Red Hat build of Apache Camel for Spring Boot 4 netty-codec-smtp Red Hat build of Debezium 2 netty-codec-smtp Red Hat build of Debezium 3 netty-codec-smtp Red Hat Data Grid 8 netty-codec-smtp
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Fuse 7 netty-codec-smtp
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat JBoss Enterprise Application Platform 7 netty-codec-smtp Red Hat JBoss Enterprise Application Platform 8 netty-codec-smtp Red Hat JBoss Enterprise Application Platform Expansion Pack netty-codec-smtp Red Hat Process Automation 7 netty-codec-smtp Red Hat Single Sign-On 7 netty-codec-smtp Red Hat streams for Apache Kafka 3 netty-codec-smtp
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
12 mo ago

Exploit prediction

1.55% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.5 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
CNA 4.0 5.5 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
maven io.netty:netty-codec-smtp
>=4.2.0.Alpha1, <4.2.7.Final
<4.1.128.Final
4.2.7.Final
4.1.128.Final

Affected products

  • netty netty

Classification

Weakness
  • CWE-93 Improper Neutralization of CRLF Sequences
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.