# Open Babel NULL pointer dereference in ChemKinFormat

Source: https://junglewise.ai/threats/open-babel-null-pointer-dereference-in-chemkinformat-bd76c929  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-09-26. Updated: 2026-07-01  
License: CC BY 4.0 with a link back

Severity: low · CVSS 3.3 · Published 2025-09-26

Open Babel, a chemical toolbox used for processing molecular data, is vulnerable to a crash when processing specifically crafted ChemKin files. An attacker with local access to the system could provide a malformed file that causes the application to stop responding. This issue primarily impacts the availability of the software during data conversion tasks.

Technologies: [openbabel (PyPI)](https://junglewise.ai/threats/technologies/openbabel). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Low severity, with a CVSS score of 3.3, published 26 September 2025.

**Which products and versions are affected?** openbabel (PyPI) < 3.2.0.

**Is there a fix for This vulnerability?** A patch was published on 2026-07-01: Version 3.2.0 identified as patched version in withdrawn duplicate advisory Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked with local access, in a software library.

**Am I affected?** Check whether you run openbabel (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A NULL pointer dereference exists in the ChemKinFormat::ReadReactionQualifierLines function within src/formats/chemkinformat.cpp of Open Babel. The vulnerability is triggered when the parser assumes a non-null string while calling c_str() during token comparison of malformed ChemKin input. An attacker with local access can provide a crafted file to trigger a segmentation fault (SEGV), resulting in a denial-of-service. This issue was identified via fuzzing and is addressed in version 3.2.0.

## Affected products

- Open Babel Open Babel < 3.2.0

## Timeline

- 2025-09-14: disclosed: Issue reported on GitHub with PoC
- 2025-09-26: advisory: Initial GHSA and NVD publication
- 2026-07-01: patched: Version 3.2.0 identified as patched version in withdrawn duplicate advisory

## References

- [https://github.com/openbabel/openbabel/issues/2829](https://github.com/openbabel/openbabel/issues/2829)
- [https://github.com/user-attachments/files/22318526/poc.zip](https://github.com/user-attachments/files/22318526/poc.zip)
- [https://vuldb.com/?ctiid.325926](https://vuldb.com/?ctiid.325926)
- [https://vuldb.com/?id.325926](https://vuldb.com/?id.325926)
- [https://vuldb.com/?submit.654063](https://vuldb.com/?submit.654063)

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