# CVE-2025-10996: Open Babel heap buffer overflow in SMILES OBSmilesParser::ParseSmiles

Source: https://junglewise.ai/threats/cve-2025-10996-open-babel-heap-buffer-overflow-in-smiles-obsmilesparser  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-30. Updated: 2026-06-30  
License: CC BY 4.0 with a link back

CVE-2025-10996 · Severity: high · CVSS 7.8 · Published 2026-06-30

Open Babel is a widely used chemistry software library and command-line tool for converting between different chemical file formats. A vulnerability in its SMILES (Simplified Molecular Input Line Entry System) parser allows a specially crafted chemical string to cause a memory crash. If an application or service uses Open Babel to process untrusted chemical data, an attacker could potentially execute malicious code or cause the system to crash, leading to data theft or service disruption.

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

## Quick answers

**Is CVE-2025-10996 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-10996 being exploited in the wild.

**How severe is CVE-2025-10996?** High severity, with a CVSS score of 7.8, published 30 June 2026.

**Which products and versions are affected?** openbabel (PyPI) < 3.2.0, ECOSYSTEM:introduced=0,fixed=3.2.0.

**Is there a fix for CVE-2025-10996?** Yes. openbabel (PyPI): upgrade to 3.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2025-10996 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2025-10996?** 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.

## How to fix

- openbabel (PyPI): upgrade to 3.2.0 or later

  ```sh
  pip install "openbabel>=3.2.0"
  ```


## Technical details

A heap buffer overflow exists in the OBSmilesParser::ParseSmiles function within src/formats/smilesformat.cpp of Open Babel. The vulnerability is triggered when the parser handles malformed SMILES input strings, leading to an out-of-bounds write on a heap-allocated buffer. An attacker can exploit this by providing a malicious SMILES string to the obabel CLI tool, the OBConversion API, or any of the supported language bindings (such as Python, Java, or C#). This can result in arbitrary code execution or a denial-of-service condition. The issue was identified via OSS-Fuzz and is resolved in version 3.2.0.

## Affected products

- Open Babel openbabel <= 3.1.1

## Identifiers

- CVE-2025-10996
- GHSA-j35x-w4gj-pf7w
- PYSEC-2026-2781

## Timeline

- 2025-09-14: disclosed: Initial bug report on GitHub
- 2025-09-25: other: CVE assigned and published to VulDB
- 2026-05-26: patched: Version 3.2.0 released
- 2026-06-30: advisory: GitHub Advisory published

## References

- [https://github.com/openbabel/openbabel/security/advisories/GHSA-j35x-w4gj-pf7w](https://github.com/openbabel/openbabel/security/advisories/GHSA-j35x-w4gj-pf7w)
- [https://github.com/openbabel/openbabel/issues/2831](https://github.com/openbabel/openbabel/issues/2831)
- [https://github.com/openbabel/openbabel/pull/2913](https://github.com/openbabel/openbabel/pull/2913)
- [https://github.com/openbabel/openbabel/commit/b34cd604](https://github.com/openbabel/openbabel/commit/b34cd604)
- [https://github.com/user-attachments/files/22318556/poc.zip](https://github.com/user-attachments/files/22318556/poc.zip)

## Related threats

- [Open Babel out-of-bounds write in MOPAC output parser](https://junglewise.ai/threats/cve-2022-46292-open-babel-out-of-bounds-write-in-mopac-output-parser)
- [Open Babel out-of-bounds write in MSI parser translationVectors](https://junglewise.ai/threats/cve-2022-46295-open-babel-out-of-bounds-write-in-msi-parser-translationvectors)
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- [Open Babel out-of-bounds write in MOPAC output parser](https://junglewise.ai/threats/cve-2022-46293-open-babel-out-of-bounds-write-in-mopac-output-parser)
- [Open Babel out-of-bounds write in Gaussian translationVectors](https://junglewise.ai/threats/cve-2022-46291-open-babel-out-of-bounds-write-in-gaussian-translationvectors)