GHSA-wx6g-fm6f-w822: MaterialX Stack Overflow via Lack of MTLX XML Parsing Recursion Limit

Summary

When parsing an MTLX file with multiple nested nodegraph implementations, the MaterialX XML parsing logic can potentially crash due to stack exhaustion.

Details

By specification, multiple kinds of elements in MTLX support nesting other elements, such as in the case of nodegraph elements. Parsing these subtrees is implemented via recursion, and since there is no max depth imposed on the XML document, this can lead to a stack overflow when the library parses an MTLX file with an excessively high number of nested elements.

PoC

Please download the recursion_overflow.mtlx file from the following link:

https://github.com/ShielderSec/poc/tree/main/CVE-2025-53009

build/bin/MaterialXView --material recursion_overflow.mtlx

Impact

An attacker could intentionally crash a target program that uses OpenEXR by sending a malicious MTLX file.

References

• GHSA-wx6g-fm6f-w822
• https://github.com/ShielderSec/poc/tree/main/CVE-2025-53009