A memory-safety vulnerability in Open Babel's ORCA parser allowed an out-of-bounds write when reading a crafted input file.
The flaw was in the nAtoms handling of the ORCA reader. A malformed
input caused the parser to write past the end of its destination
buffer.
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).
All releases up to and including 3.1.1.
3.2.0 (released 2026-05-26).
Fix commit: https://github.com/openbabel/openbabel/commit/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.
Reported by Cisco TALOS.