`CVE-2025-59419`

Severity	5.5 Medium CVSS 4.0
Fixed in	`4.2.7.Final`, `4.1.128.Final`
Weakness	OS command injection (CWE-78)
Published	15 Oct 2025
Updated	19 Oct 2026

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.

CWE-93

Exploitation status

Proof of concept only

A proof of concept exists, but no reviewed exploit catalogue lists this CVE.

CISA KEV not listed
VulnCheck KEV not listed
CISA Vulnrichment exploitation: poc CISA recorded that an exploit has been demonstrated. Automatable: yes, technical impact: partial.
Indexed PoC none indexed
EPSS 1.6% chance in 30 days

Waratek protection

Protected by Waratek

Waratek has a rule that blocks attacks on this vulnerability.

Protection full Process
Action available security rule
Review automated Inferred
Record active

Decided by	A vulnerability class already blocked by an ARMR security rule
Finding	Protected by Waratek's ARMR command-injection security rule, which blocks this class of attack at the JVM level without a rule written for this CVE specifically. The CVE's weakness is CWE-78: OS Command Injection.
Candidate fix	https://github.com/netty/netty/commit/1782e8c2060a244c4d4e6f9d9112d5517ca05120 : a commit: the change itself

Decided by

A vulnerability class already blocked by an ARMR security rule

Finding

Protected by Waratek's ARMR command-injection security rule, which blocks this class of attack at the JVM level without a rule written for this CVE specifically. The CVE's weakness is CWE-78: OS Command Injection.

Candidate fix

https://github.com/netty/netty/commit/1782e8c2060a244c4d4e6f9d9112d5517ca05120 : a commit: the change itself

How to mitigate CVE-2025-59419

Upgrade the affected software to a release that fixes it: 4.2.7.Final or 4.1.128.Final. Until you can, Waratek RASP blocks exploitation with its process rule. It runs inside the Java application, with no code changes.

Waratek RASP Runtime protection for Java applications

Affected software and releases

Oracle advisories

Advisory	Type	Quarter	Products Oracle names in its risk matrix
Oracle Critical Patch Update April 2026 ↗	CPU	2026-Q2	Oracle Analytics / Platform Security (netty-codec-smtp) (8.2.0.0.0)
Oracle Critical Patch Update January 2026 ↗	CPU	2026-Q1	Oracle GoldenGate / Java Delivery (Netty) (21.3-21.20, 23.4-23.10)

Advisory

Type

Quarter

Products Oracle names in its risk matrix

Oracle Critical Patch Update April 2026 ↗

CPU

2026-Q2

Oracle Analytics / Platform Security (netty-codec-smtp) (8.2.0.0.0)

Oracle Critical Patch Update January 2026 ↗

CPU

2026-Q1

Oracle GoldenGate / Java Delivery (Netty) (21.3-21.20, 23.4-23.10)

Oracle components and versions

Family	Component	Versions, as Oracle lists them	Read as
Oracle Analytics	Platform Security (netty-codec-smtp)	8.2.0.0.0	8.2.0.0.0
Oracle GoldenGate	Java Delivery (Netty)	21.3-21.20, 23.4-23.10

Maven packages

Affected and fixed versions, from OSV.dev

Package Introduced Fixed Last affected

io.netty:netty-codec-smtp 4.2.0.Alpha1 4.2.7.Final unbounded

io.netty:netty-codec-smtp 0 4.1.128.Final unbounded

Package	Introduced	Fixed	Last affected
`io.netty:netty-codec-smtp`	4.2.0.Alpha1	`4.2.7.Final`	unbounded
`io.netty:netty-codec-smtp`	0	`4.1.128.Final`	unbounded

Products and versions

1 product, 2 version entries

Source	Vendor	Product	Scheme	Affected versions
osv	io.netty	netty-codec-smtp	generic	＜ 4.1.128 · ≥ 4.2.0 and ＜ 4.2.7

Source

Vendor

Product

Scheme

Affected versions

osv

io.netty

netty-codec-smtp

generic

＜ 4.1.128 · ≥ 4.2.0 and ＜ 4.2.7

References

URL	Tags
https://github.com/netty/netty/commit/1782e8c2060a244c4d4e6f9d9112d5517ca05120	commit
https://github.com/netty/netty/security/advisories/GHSA-jq43-27x9-3v86	WEB
https://github.com/netty/netty/commit/2b3fddd3339cde1601f622b9ce5e54c39f24c3f9	WEB
https://gist.github.com/DepthFirstDisclosures/ddacca28cb94b48fa8ab998cef59ed8c	WEB
https://github.com/netty/netty	PACKAGE
https://www.depthfirst.com/post/our-ai-agent-found-a-netty-zero-day-that-bypasses-email-authentication-the-story-of-cve-2025-59419	WEB

URL

Timeline

Published	2025-10-15	By the CVE Program.
NVD record modified	2026-10-19	NVD's own last-modified date for this record.

Published

2025-10-15

By the CVE Program.

NVD record modified

2026-10-19

NVD's own last-modified date for this record.

How VRT decided (17 of 24 rules ran)

17 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file no match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no match An ARMR security-rule template on disk for this CVE

4 manual-classification no match A researcher's recorded decision for this specific CVE

5 manual classification no match Manual classification of this CVE in the legacy dataset

6 non-java-upstream no match A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component no match The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side no match Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven matched In scope Maven packages: io.netty:netty-codec-smtp

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint matched Mitigation candidate References include candidate fix URL (commit tier): https://github.com/netty/netty/commit/1782e8c2060a244c4d4e6f9d9112d5517ca05120

18 open-source-maven skipped The affected package being open source on Maven, so the fix can be read

19 poc-derivable skipped An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit skipped Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match decided it matched Protected by Waratek CWE-78 (OS Command Injection) is mitigable by an ARMR command-injection security rule.

22 exploited-no-fix-or-poc skipped Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold skipped Medium or Low severity, no CISA or VulnCheck KEV listing, no PoC clearing the evidence bar, no CISA verdict, no Oracle advisory

24 no-exploit-published skipped Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all

NVD ↗ · CVE.org ↗