Description
Improper Input Validation, Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Apache Camel Mail Component.

The camel-mail producer (MailProducer.getSender) scanned the outgoing Exchange for message headers in the mail.smtp. / mail.smtps. namespace and, when any were present, built a per-message JavaMail sender with those values applied as JavaMail session properties, overriding the endpoint configuration. This namespace is Camel-internal - only MailProducer interprets it - and was not blocked by any HeaderFilterStrategy, so the values could originate from any inbound protocol (for example platform-http query parameters or request headers, or JMS / Kafka messages from untrusted producers) that feeds a route ending in an smtp / smtps producer without an intervening removeHeaders. The maximal impact is version-dependent: on releases before 4.19.0, setting mail.smtp.host redirects the SMTP connection to a server under the attacker's control, and because the producer then authenticates with the endpoint's configured username and password those credentials are transmitted to the attacker; on 4.19.0 and later the producer connects to the endpoint's configured host explicitly, so the reachable impact is limited to weakening transport security (for example mail.smtp.ssl.trust, mail.smtp.starttls.enable or mail.smtp.socks.host) and interception of the outgoing message rather than host redirect. Exploitation requires a route that channels untrusted input into the mail producer without stripping the namespace.
This issue affects Apache Camel: from 4.0.0 before 4.14.8, from 4.15.0 before 4.18.3, from 4.19.0 before 4.21.0.

Users are recommended to upgrade to version 4.21.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.8. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.3. After upgrading, the per-message override is disabled by default; enable it only on trusted endpoints with useJavaMailSessionPropertiesFromHeaders=true. For deployments that cannot upgrade immediately, strip the namespace before the mail producer with removeHeaders('mail.smtp.*') and removeHeaders('mail.smtps.*') between any untrusted ingress and the smtp / smtps producer. Even with the opt-in enabled, route authors should still strip the namespace on any path that carries untrusted input.
Published: 2026-07-06
Score: 3.7 Low
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

Apache Camel Mail accepts headers prefixed with mail.smtp. or mail.smtps. from an incoming Exchange and injects them as JavaMail session properties on a per‑message basis, bypassing internal validation. In versions prior to 4.19.0 this allows an attacker to set mail.smtp.host to an arbitrary SMTP server, causing the producer to use the configured username and password and deliver them to the attacker. In 4.19.0 and later the host override is disabled, but an attacker can still weaken transport security by manipulating properties such as mail.smtp.ssl.trust, mail.smtp.starttls.enable, or mail.smtp.socks.host, or intercept the message content.

Affected Systems

The flaw affects the Apache Camel Mail component from the Apache Software Foundation in all releases 4.0.0 through 4.14.8, 4.15.0 through 4.18.3, and 4.19.0 through 4.21.0. Any Camel route that produces email via SMTP or SMTPS and does not strip the mail.smtp.* and mail.smtps.* headers from untrusted input is vulnerable.

Risk and Exploitability

The CVSS base score of 3.7 indicates low severity, and the EPSS score of less than 1 % indicates an extremely low likelihood of exploitation. The vulnerability is not listed in the CISA KEV catalog. Exploitation requires untrusted data to reach the mail producer without header removal, which can occur through HTTP query parameters, JMS, or Kafka messages. In pre‑4.19.0 releases this can trigger credential leakage, while in 4.19.0 and later the impact is limited to transport security weakening or message interception. Overall risk remains low, but the potential for credential exposure warrants prompt remediation.

Generated by OpenCVE AI on August 3, 2026 at 05:12 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade Apache Camel Mail to version 4.21.0 (or to 4.18.3 if on the 4.18.x stream or to 4.14.8 if on the 4.14.x LTS stream) to disable per‑message override by default.
  • Insert removeHeaders('mail.smtp.*') and removeHeaders('mail.smtps.*') in any route that processes untrusted input before it reaches an smtp or smtps producer.
  • If the useJavaMailSessionPropertiesFromHeaders=true option is required, restrict its use to routes that never accept external data and ensure the mail.* headers are removed on any untrusted path.

Generated by OpenCVE AI on August 3, 2026 at 05:12 UTC.

Tracking

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Advisories

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History

Wed, 08 Jul 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-918
References
Metrics threat_severity

None

 threat_severity

Moderate

Mon, 06 Jul 2026 23:15:00 +0000

Type Values Removed Values Added
First Time appeared Apache
Apache camel Mail
Vendors & Products Apache
Apache camel Mail

Mon, 06 Jul 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 06 Jul 2026 09:00:00 +0000

Type Values Removed Values Added
Description Improper Input Validation, Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Apache Camel Mail Component. The camel-mail producer (MailProducer.getSender) scanned the outgoing Exchange for message headers in the mail.smtp. / mail.smtps. namespace and, when any were present, built a per-message JavaMail sender with those values applied as JavaMail session properties, overriding the endpoint configuration. This namespace is Camel-internal - only MailProducer interprets it - and was not blocked by any HeaderFilterStrategy, so the values could originate from any inbound protocol (for example platform-http query parameters or request headers, or JMS / Kafka messages from untrusted producers) that feeds a route ending in an smtp / smtps producer without an intervening removeHeaders. The maximal impact is version-dependent: on releases before 4.19.0, setting mail.smtp.host redirects the SMTP connection to a server under the attacker's control, and because the producer then authenticates with the endpoint's configured username and password those credentials are transmitted to the attacker; on 4.19.0 and later the producer connects to the endpoint's configured host explicitly, so the reachable impact is limited to weakening transport security (for example mail.smtp.ssl.trust, mail.smtp.starttls.enable or mail.smtp.socks.host) and interception of the outgoing message rather than host redirect. Exploitation requires a route that channels untrusted input into the mail producer without stripping the namespace. This issue affects Apache Camel: from 4.0.0 before 4.14.8, from 4.15.0 before 4.18.3, from 4.19.0 before 4.21.0. Users are recommended to upgrade to version 4.21.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.8. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.3. After upgrading, the per-message override is disabled by default; enable it only on trusted endpoints with useJavaMailSessionPropertiesFromHeaders=true. For deployments that cannot upgrade immediately, strip the namespace before the mail producer with removeHeaders('mail.smtp.*') and removeHeaders('mail.smtps.*') between any untrusted ingress and the smtp / smtps producer. Even with the opt-in enabled, route authors should still strip the namespace on any path that carries untrusted input.
Title Apache Camel Mail: The mail producer applied attacker-supplied message headers as JavaMail session properties, allowing an attacker to influence SMTP parameters
Weaknesses CWE-20
CWE-200
References

Subscriptions

Apache Camel Camel Mail
cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published:

Updated: 2026-07-06T19:26:03.975Z

Reserved: 2026-05-15T07:52:46.176Z

Link: CVE-2026-46584

cve-icon Vulnrichment

Updated: 2026-07-06T09:25:18.675Z

cve-icon NVD

Status : Analyzed

Published: 2026-07-06T09:16:36.927

Modified: 2026-07-08T15:06:26.423

Link: CVE-2026-46584

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-06T08:02:37Z

Links: CVE-2026-46584 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-03T05:15:18Z

Weaknesses
  • CWE-20

    Improper Input Validation

  • CWE-200

    Exposure of Sensitive Information to an Unauthorized Actor

  • CWE-918

    Server-Side Request Forgery (SSRF)