GHSA-vjg6-gm8m-v5g6

### Summary

A memory-safety vulnerability in Open Babel's MOL2 parser allowed an out-of-bounds write when reading a crafted input file.

### Details

The flaw was in the attribute/value parsing path of the MOL2 reader. An over-long attribute or value caused the parser to write past the end of a fixed-size 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 MOL2 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/4110d59a

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.