Summary
quarkus-openapi-generator extension has Zip Slip Path Traversal in ApicurioCodegenWrapper class
A path traversal vulnerability was discovered in the quarkus-openapi-generator extension
Details
The unzip() method in ApicurioCodegenWrapper.java extracts ZIP entries without validating that the resolved file path stays within the intended output directory. At line 101, the destination is constructed as new File(toOutputDir, entry.getName()) and the content is written immediately. A malicious ZIP archive containing entries with path traversal sequences (e.g., ../../malicious.java) would write files outside the target directory.
The interesting thing is that the client module in the same repository already has the correct fix. OpenApiGeneratorStreamCodeGen.java at line 137 performs proper normalize() and startsWith() validation. The server module was simply missed.
PoC
This vulnerability is exploitable when an attacker controls or can intercept the ZIP archive served by the Apicurio registry. In environments where the registry connection is over an untrusted network or where TLS is not properly configured, exploitation becomes practical. The attack occurs at build/codegen time.
- Create a ZIP file containing an entry named
../../proof.txtwith arbitrary content - Configure quarkus-openapi-generator to use the server (Apicurio) code generation path
- Serve the malicious ZIP from a controlled or MITM'd Apicurio registry endpoint
- Trigger code generation
- Observe that
proof.txtis written two directories above the intended output
Impact
An attacker who can serve a crafted ZIP to the code generation pipeline could write arbitrary files on the build machine. This could overwrite source files, inject malicious code into the build output, or modify configuration files. In CI/CD environments, this could lead to supply chain compromise.
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
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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Frequently Asked Questions
- What is CVE-2026-40180? CVE-2026-40180 is a medium-severity path traversal vulnerability in io.quarkiverse.openapi.generator:quarkus-openapi-generator (maven), affecting versions <= 2.15.0. It is fixed in 2.16.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- Which versions of io.quarkiverse.openapi.generator:quarkus-openapi-generator are affected by CVE-2026-40180? io.quarkiverse.openapi.generator:quarkus-openapi-generator (maven) versions <= 2.15.0 is affected.
- Is there a fix for CVE-2026-40180? Yes. CVE-2026-40180 is fixed in 2.16.0. Upgrade to this version or later.
- Is CVE-2026-40180 exploitable, and should I be worried? Whether CVE-2026-40180 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-2026-40180 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-2026-40180? Upgrade
io.quarkiverse.openapi.generator:quarkus-openapi-generatorto 2.16.0 or later.