CVE-2026-33454

CRITICAL LAB

Apache Camel MailHeaderFilterStrategy - MIME Header Injection RCE

Title source: manual
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-33454. PoCs published by oscerd.

AI-analyzed exploit summary This repository demonstrates a header injection vulnerability in Apache Camel's camel-mail component (CVE-2026-33454) where unfiltered MIME headers are mapped into Exchange headers, enabling RCE when forwarded to a header-sensitive producer like camel-exec. The PoC includes a Spring Boot application with an exploit controller and victim route, plus a Dockerized GreenMail server for testing.

Description

The Camel-Mail component is vulnerable to Camel message header injection. The custom header filter strategy used by the component (MailHeaderFilterStrategy) only filters the 'out' direction via setOutFilterStartsWith, while it does not configure the 'in' direction via setInFilterStartsWith. As a result, when a Camel application consumes mail through camel-mail (for example via from(\"imap://...\") or from(\"pop3://...\")) the inbound filter check is skipped and Camel-prefixed MIME headers are mapped unfiltered into the Exchange. An attacker who can deliver an email to a mailbox monitored by such a consumer can inject Camel-specific headers that, for some Camel components downstream of the mail consumer (such as camel-bean, camel-exec, or camel-sql), can alter the behaviour of the route. This is the same pattern that was previously addressed in camel-undertow (CVE-2025-30177) and the broader incoming-header filter (CVE-2025-27636 and CVE-2025-29891). This issue affects Apache Camel: from 3.0.0 before 4.14.6, from 4.15.0 before 4.18.1. Users are recommended to upgrade to version 4.19.0, which fixes the issue. If users are on the 4.18.x LTS releases stream, then they are suggested to upgrade to 4.18.1. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.6.

Exploits (1)

github WORKING POC
by oscerd · javapoc
https://github.com/oscerd/CVE-2026-33454

This repository demonstrates a header injection vulnerability in Apache Camel's camel-mail component (CVE-2026-33454) where unfiltered MIME headers are mapped into Exchange headers, enabling RCE when forwarded to a header-sensitive producer like camel-exec. The PoC includes a Spring Boot application with an exploit controller and victim route, plus a Dockerized GreenMail server for testing.

Classification
Working Poc 99%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Apache Camel camel-mail component versions before 4.14.6, 4.18.1, and 4.19.0
No auth needed
Prerequisites: Attacker must be able to deliver an email to a mailbox monitored by a Camel mail consumer · Victim route must forward messages to a header-sensitive producer (e.g., camel-exec)
mistral-large-3 · analyzed Jul 06, 2026 Full analysis →

Scores

CVSS v3 9.4
EPSS 0.0062
EPSS Percentile 46.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Lab Environment

COMMUNITY
Community Lab
docker pull greenmail/standalone:2.1.0

Details

CWE
CWE-1173 CWE-502
Status published
Products (4)
apache/camel 3.0.0 - 4.14.6
Apache Software Foundation/Apache Camel 3.0.0 - 4.14.6
Apache Software Foundation/Apache Camel 4.15.0 - 4.18.1
org.apache.camel/camel-mail 3.0.0 - 4.14.6Maven
Published Apr 27, 2026
Tracked Since Apr 27, 2026