High 7.5Published Sep 18, 2026

CVE-2026-93563Io.netty/netty-codec-smtp: netty: unbounded multi-line response accumulation in smtpresponsedecoder leads to memory-exhaustion dos

Updated under an hour ago (2026-10-19 08:50 UTC)

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It affects Red Hat build of Apache Camel for Spring Boot 4 and 3 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Red Hat build of Apache Camel for Spring Boot 4

Exploited in the last 30 days

A flaw was found in Netty's `SmtpResponseDecoder` component. A remote attacker, acting as a malicious or man-in-the-middle (MITM) SMTP server, could exploit this by sending a specially crafted, unbounded multi-line SMTP response without a terminator. This vulnerability leads to unbounded memory accumulation within the client's Java Virtual Machine (JVM) heap, causing an `OutOfMemoryError` and a denial of service (DoS) due to a process crash.

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-1035
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: redhat
NVD analysis: Awaiting Analysis
Record last updated: Sep 25, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Red Hat Red Hat build of Apache Camel for Spring Boot 4 redhat:camel_spring_boot	4	CNA record
Red Hat Red Hat Fuse 7 redhat:jboss_fuse	7	CNA record
Red Hat Red Hat JBoss Enterprise Application Platform 7 redhat:jboss_enterprise_application_platform	7	CNA record
Red Hat Red Hat Single Sign-On 7 redhat:red_hat_single_sign_on	7	CNA record

References

https://access.redhat.com/security/cve/CVE-2026-93563vdb-entry, x-refsource-redhat
https://bugzilla.redhat.com/show_bug.cgi?id=2536976issue-tracking, x-refsource-redhat

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.