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Open Babel has out-of-bounds write in ORCA nAtoms parser (second variant)

High severity GitHub Reviewed Published May 27, 2026 in openbabel/openbabel • Updated Jul 1, 2026

Package

pip openbabel (pip)

Affected versions

< 3.2.0

Patched versions

3.2.0

Description

Summary

A memory-safety vulnerability in Open Babel's ORCA parser allowed an
out-of-bounds write when reading a crafted input file.

Details

A second variant of the nAtoms out-of-bounds write in the ORCA
reader: a different malformed-input path produced the same class of
write past the end of the destination buffer.

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 ORCA 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: openbabel/openbabel@b239d06e

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 by Cisco TALOS.

References

@ghutchis ghutchis published to openbabel/openbabel May 27, 2026
Published to the GitHub Advisory Database Jul 1, 2026
Reviewed Jul 1, 2026
Last updated Jul 1, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(53rd percentile)

Weaknesses

Heap-based Buffer Overflow

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Learn more on MITRE.

Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer. Learn more on MITRE.

CVE ID

CVE-2022-46290

GHSA ID

GHSA-5rff-8f7c-8jmw

Source code

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