GHSA-pcc4-rvhr-2pr8: Graphify Fortran extractor: incomplete cpp #include hardening allows arbitrary host-file read/exfiltration when indexing an untrusted repo

The Fortran extractor’s C-preprocessor step (graphify/extractors/fortran.py, _cpp_preprocess) applies an incomplete #include hardening. The -nostdinc -I /dev/null flags it relies on (comment “Security (F-007)”) do not stop a capital-F Fortran source file from including absolute paths (#include "/etc/passwd") or from path-traversing out of the corpus (#include "../../../../home/victim/.ssh/id_rsa"). cpp always searches the directory of the file being preprocessed for quoted includes and always honours absolute include paths, regardless of -nostdinc/-I. As a result, indexing an untrusted repository that contains a .F/.F90/.F95/.F03/.F08 file reads arbitrary local files off the host and inlines their contents into the knowledge graph, which is then shipped to the LLM/agent and written to the on-disk, shareable output (graph.json, GRAPH_REPORT.md, the Obsidian wiki, HTML/SVG exports).

This is the exact “corpus-side file-exfiltration vector” the F-007 comment says it is defending against; the mitigation is bypassable.