Apache Camel Security Advisory - CVE-2026-40047

Apache Camel security advisory: CVE-2026-40047

Severity

MEDIUM

Summary

Camel-Docling: Insufficient validation of custom CLI arguments enables argument injection and path traversal in DoclingProducer

Versions affected

From 4.15.0 before 4.18.3.

Versions fixed

4.18.3 and 4.19.0

Description

The camel-docling component invokes the external `docling` command-line tool by assembling an argument list in DoclingProducer and executing it through java.lang.ProcessBuilder. Custom CLI arguments supplied through the `CamelDoclingCustomArguments` exchange header (a List<String>) were appended to that argument list with insufficient validation: the original implementation relied on a denylist of disallowed flags and only rejected path values that contained a literal `../` sequence. As a result, a Camel route that forwards externally-influenced data into the `CamelDoclingCustomArguments` header (or into the path-bearing headers used to build the invocation) could cause the producer to pass unrecognized or unintended `docling` CLI flags to the subprocess, and could supply path-like argument values that resolved outside the intended directory through traversal sequences not caught by the literal `../` check. Because Camel itself builds the `docling` invocation from these values, the component is responsible for constraining them, and the weak validation allowed CLI-argument injection and directory traversal in the arguments passed to the external tool. The invocation uses the list-based form of ProcessBuilder, so a shell does not interpret the argument values; OS command injection through shell metacharacters was not possible, and the metacharacter rejection added by the fix is defense-in-depth.

Notes

The JIRA ticket: https://issues.apache.org/jira/browse/CAMEL-23212 refers to the commits that resolved the issue, and has more details.

The fix was merged on the main branch in https://github.com/apache/camel/pull/22082 (commit f86fda0442c65b9d13ce3aa8ac676233b64e3351) and is first available in the 4.19.0 release. The 4.18.x LTS backport is https://github.com/apache/camel/pull/22767 (commit 1fa56f45901f50aa79849ff2d2ca83dd57f6991c) and is included in the 4.18.3 release.

Mitigation

Users are recommended to upgrade to a release that contains the CAMEL-23212 fix. On the mainline the fix is included from Apache Camel 4.19.0 (and later releases such as 4.20.0). For users on the 4.18.x LTS releases stream, upgrade to 4.18.3. The fix replaces the denylist with a strict allowlist of recognized docling CLI flags (rejecting any unrecognized flag, and rejecting producer-managed flags such as the output-directory flags), defensively rejects shell metacharacters in argument values, and normalizes path-like values with Path.normalize() before validating them so that traversal sequences which bypass a literal ../ check are detected. As defence in depth, route authors should avoid mapping untrusted message content into the CamelDoclingCustomArguments header and the path-bearing headers, and should strip Camel-internal headers from messages that arrive from untrusted producers.

Credit

This issue was discovered by Andrea Cosentino from Apache Software Foundation

References

PGP signed advisory data: CVE-2026-40047.txt.asc
Mitre CVE Entry: https://www.cve.org/CVERecord?id=CVE-2026-40047