---
id: CVE-2025-10999
title: 'Open Babel has NULL pointer dereference in CACAO CacaoFormat::SetHilderbrandt'
summary: 'Open Babel has NULL pointer dereference in CACAO CacaoFormat::SetHilderbrandt'
severity: medium
cvss: 5.5
cwe:
  - CWE-404
  - CWE-476
vendor: openbabel
product: openbabel
ecosystem: pip
affected:
  - openbabel < 3.2.0
patched:
  - openbabel 3.2.0
published: '2026-07-01'
updated: '2026-07-01'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-55j6-rjhx-hwfh'
references:
  - url: >-
      https://github.com/openbabel/openbabel/security/advisories/GHSA-55j6-rjhx-hwfh
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-10999'
  - url: 'https://github.com/openbabel/openbabel/issues/2827'
  - url: 'https://github.com/openbabel/openbabel/commit/ecaed96f'
  - url: 'https://github.com/user-attachments/files/22318503/poc.zip'
  - url: 'https://vuldb.com/?ctiid.325927'
  - url: 'https://vuldb.com/?id.325927'
  - url: 'https://vuldb.com/?submit.654064'
  - url: 'https://github.com/advisories/GHSA-55j6-rjhx-hwfh'
tags:
  - ghsa
  - pip
epss: 0.00247
epssPercentile: 0.14217
ingestedAt: '2026-07-01T18:15:20.591Z'
---

## Overview

### 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.

## Affected packages

- `openbabel < 3.2.0`

## Remediation

Upgrade to a patched release:

- `openbabel 3.2.0`