CVE-2026-93576: Io.netty/netty-codec-smtp: netty netty-codec-smtp — smtp command-name field is not crlf-validated (incomplete fix of cve-2025-59419)

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-18 · updated 2026-09-25
Weakness: CWE-93

Description

A flaw was found in Netty netty-codec-smtp. The component does not properly validate Carriage Return (CR) and Line Feed (LF) characters in the SMTP command-name field. A remote attacker, if an application routes untrusted input into this field, can embed CR/LF characters to inject arbitrary SMTP commands. This can lead to SMTP command smuggling, allowing for unauthorized email relay or spoofing of sender/recipient addresses. While the impact is significant, the real-world exploitability is considered lower as applications typically do not place user-controlled data in the command-name field.

Affected products

Red Hat build of Apache Camel for Spring Boot 4: all versions
Red Hat JBoss Enterprise Application Platform 7: all versions
Red Hat Single Sign-On 7: all versions

References

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