Summary
Apache Camel-Mail: the MimeMultipart data format copied MIME headers onto the Camel message without a header filter strategy when unmarshalling with headersInline enabled
Improper input validation vulnerability in Apache Camel.
This issue affects Apache Camel: from 2.17.0 before 4.14.9, from 4.15.0 before 4.18.4, from 4.19.0 before 4.22.0.
The camel-mail component ships a MimeMultipart data format that can unmarshal a MIME multipart message. When it is configured with headersInline set to true, the unmarshal path copies the MIME headers of the incoming message onto the Camel message: it enumerates every header that is not one of the three standard ones it generates itself - Message-ID, MIME-Version and Content-Type - and calls setHeader for each, applying no HeaderFilterStrategy. The names of those MIME headers come from the message being unmarshalled, so a sender able to influence the message could place a header whose name falls in the Camel-internal namespace and have it set on the Exchange. Camel components read control headers from that namespace to override their configured behaviour - the camel-sql producer, for instance, takes the statement to execute from a Camel header when one is present - so an injected header could redirect what a downstream step in the route does with data the route author never intended it to take from the message. Which sinks are reachable, and what the consequences are, depends entirely on what the route does after the unmarshal step. The camel-mail consumer already applied a header filter strategy on its own inbound path, so this was the parallel inbound path into the same component that the earlier hardening did not cover. The affected copy is reached only when headersInline is enabled, which is not the default: with the default setting the MIME headers are surfaced as attachments rather than as message headers, and are not affected. The behaviour dates back to the introduction of the data format in 2.17.0 and was present on every release line until this fix.
Users are recommended to upgrade to version 4.22.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.9. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.4. For deployments that cannot upgrade immediately, leave headersInline at its default of false where the inline headers are not needed, since the copy is only reached when it is enabled. Where it must stay enabled, strip Camel-internal headers immediately after the unmarshal step, for example with removeHeaders(“Camel*”) placed before any processor or producer that reads control headers, and do not unmarshal MIME content from an untrusted sender into a route that dispatches on header values. As defence in depth, treat the header names of any MIME message arriving from outside the trust boundary as untrusted input.
Impact
The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.
CVE-2026-59230 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.14.9, 4.18.4, 4.22.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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org.apache.camel:camel-mail to 4.14.9 or later; org.apache.camel:camel-mail to 4.18.4 or later; org.apache.camel:camel-mail to 4.22.0 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-59230? CVE-2026-59230 is a medium-severity improper input validation vulnerability in org.apache.camel:camel-mail (maven), affecting versions >= 2.17.0, < 4.14.9. It is fixed in 4.14.9, 4.18.4, 4.22.0. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
- How severe is CVE-2026-59230? CVE-2026-59230 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.apache.camel:camel-mail are affected by CVE-2026-59230? org.apache.camel:camel-mail (maven) versions >= 2.17.0, < 4.14.9 is affected.
- Is there a fix for CVE-2026-59230? Yes. CVE-2026-59230 is fixed in 4.14.9, 4.18.4, 4.22.0. Upgrade to this version or later.
- Is CVE-2026-59230 exploitable, and should I be worried? Whether CVE-2026-59230 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-59230 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-59230?
- Upgrade
org.apache.camel:camel-mailto 4.14.9 or later - Upgrade
org.apache.camel:camel-mailto 4.18.4 or later - Upgrade
org.apache.camel:camel-mailto 4.22.0 or later
- Upgrade