CVE-2025-10999 — Open Babel cacaoformat.cpp SetHilderbrandt null pointer dereference

Affected: Open Babel

A vulnerability was found in Open Babel up to 3.1.1. The impacted element is the function CacaoFormat::SetHilderbrandt of the file /src/formats/cacaoformat.cpp. The manipulation results in null pointer dereference. The attack is only possible with local access. The exploit has been made public and could be used.

GHSA-55j6-rjhx-hwfh — Open Babel has NULL pointer dereference in CACAO CacaoFormat::SetHilderbrandt

Affected: PyPI: openbabel

### Summary

A memory-safety vulnerability in Open Babel's CACAO parser caused a NULL pointer dereference when reading a crafted input file.

### Details

The flaw was in `CacaoFormat::SetHilderbrandt`. A malformed input caused the parser to dereference a NULL pointer while applying the Hilderbrandt transformation.

### Impact

Open Babel is a C++ library and CLI used to read and write chemistry file formats; it is shipped by Linux distributions and embedded in services that may parse untrusted input. Triggering this vulnerability requires the victim to open a malicious CACAO file with the `obabel` tool, the `OBConversion` API, or any of the language bindings (Python, Ruby, Java, R, Perl, C#, PHP).

### Affected versions

All releases up to and including 3.1.1.

### Patched version

3.2.0 (released 2026-05-26).

### Patch

Fix commit: https://github.com/openbabel/openbabel/commit/ecaed96f Originally reported as #2827; fixes consolidated in #2913.

A minimized reproducer for this CVE is checked in under `test/files/fuzz_regress/` and is exercised on every CI build under ASAN+UBSAN by the `fuzzregresstest` harness.

### Credit

Reported via OSS-Fuzz.

Most recent entries from all

CVE-2025-10999 — Open Babel cacaoformat.cpp SetHilderbrandt null pointer dereference

GHSA-55j6-rjhx-hwfh — Open Babel has NULL pointer dereference in CACAO CacaoFormat::SetHilderbrandt