PYSEC-2026-2787 Open Babel has uninitialized pointer dereference in GRO residue parser

Summary A memory-safety vulnerability in Open Babel's GRO parser caused an uninitialized pointer dereference when reading a crafted input file. Details The flaw was in the residue handling of the GRO reader. A malformed record caused the parser to use a residue pointer that had never been...

PYSEC-2026-2783 Open Babel has out-of-bounds write in Gaussian translationVectors[]

Summary A memory-safety vulnerability in Open Babel's Gaussian output parser allowed an out-of-bounds write into the translationVectors array when reading a crafted input file. Details The Gaussian reader stored periodic-cell translation vectors into a fixed-size translationVectors array. A...

PYSEC-2026-2780 Open Babel has out-of-bounds write in MSI translationVectors[]

Summary A memory-safety vulnerability in Open Babel's MSI parser allowed an out-of-bounds write into the translationVectors array when reading a crafted input file. Details The MSI reader stored cell translation vectors into a fixed-size translationVectors array. A malformed input could push more...

PYSEC-2026-2773 Open Babel has out-of-bounds write in ORCA nAtoms parser (second variant)

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...

Open Babel has out-of-bounds write in ORCA nAtoms parser

SummaryA memory-safety vulnerability in Open Babel's ORCA parser allowed anout-of-bounds write when reading a crafted input file. DetailsThe flaw was in the nAtoms handling of the ORCA reader. A malformedinput caused the parser to write past the end of its destinationbuffer. ImpactOpen Babel is a...

Open Babel has NULL pointer dereference in ChemKinFormat::ReadReactionQualifierLines

SummaryA memory-safety vulnerability in Open Babel's ChemKin parser causeda NULL pointer dereference when reading a crafted input file. DetailsThe flaw was in ChemKinFormat::ReadReactionQualifierLines. Amalformed reaction qualifier record caused the parser to dereferencea NULL pointer. ImpactOpen...

Open Babel has out-of-bounds write in CSR PadString (title field)

SummaryA memory-safety vulnerability in Open Babel's CSR parser allowed anout-of-bounds write when reading a crafted input file. DetailsThe flaw was in the PadString helper used to handle the CSR titlefield. A title longer than the fixed destination buffer caused theparser to write past the end o...

PYSEC-2026-2774 Open Babel has an out-of-bounds read in CIF transform3d::DescribeAsString

Summary A memory-safety vulnerability in Open Babel's CIF file format parser allowed an out-of-bounds read when reading a crafted input file. Details The flaw was in OpenBabel::transform3d::DescribeAsString. A malformed symmetry-operation string caused the parser to read past the end of its...

PYSEC-2026-2778 Open Babel has heap buffer overflow in ChemKin ChemKinFormat::CheckSpecies

Summary A memory-safety vulnerability in Open Babel's ChemKin parser caused a heap buffer overflow when reading a crafted input file. Details The flaw was in ChemKinFormat::CheckSpecies. A malformed species record caused the parser to write past the end of a heap-allocated buffer. Impact Open Bab...

PYSEC-2026-2770 Open Babel has NULL pointer dereference in MOL2 OBAtom::SetFormalCharge

Summary A memory-safety vulnerability in Open Babel's MOL2 file format parser caused a NULL pointer dereference when reading a crafted input file. Details The flaw was in OBAtom::SetFormalCharge as called from the MOL2 parser. A malformed atom record caused the parser to call the method on a NULL...

PYSEC-2026-2788 Open Babel has out-of-bounds write in CSR PadString (title field)

Summary A memory-safety vulnerability in Open Babel's CSR parser allowed an out-of-bounds write when reading a crafted input file. Details The flaw was in the PadString helper used to handle the CSR title field. A title longer than the fixed destination buffer caused the parser to write past the...

PYSEC-2026-2789 Open Babel has Use-after-free in GAMESS GAMESSOutputFormat::ReadMolecule

Summary A memory-safety vulnerability in Open Babel's GAMESS output parser caused a use-after-free when reading a crafted input file. Details The flaw was in GAMESSOutputFormat::ReadMolecule. A malformed input caused the parser to dereference a stale pointer after the underlying object had been...

PYSEC-2026-2791 Open Babel has a NULL pointer dereference in CDXML OBAtom::GetExplicitValence

Summary A memory-safety vulnerability in Open Babel's CDXML file format parser caused a NULL pointer dereference when reading a crafted input file. Details The flaw was in OBAtom::GetExplicitValence as called from the CDXML parser. A malformed fragment caused the parser to invoke the method on a...

PYSEC-2026-2781 Open Babel has heap buffer overflow in SMILES OBSmilesParser::ParseSmiles

Summary A memory-safety vulnerability in Open Babel's SMILES parser caused a heap buffer overflow when reading a crafted input string. Details The flaw was in OBSmilesParser::ParseSmiles. A malformed SMILES input caused the parser to write past the end of a heap-allocated buffer. Impact Open Babe...

Open Babel has heap buffer overflow in ChemKin ChemKinFormat::CheckSpecies

SummaryA memory-safety vulnerability in Open Babel's ChemKin parser causeda heap buffer overflow when reading a crafted input file. DetailsThe flaw was in ChemKinFormat::CheckSpecies. A malformed speciesrecord caused the parser to write past the end of a heap-allocatedbuffer. ImpactOpen Babel is ...

PYSEC-2026-2776 Open Babel has out-of-bounds write (overlapping memcpy) in zipstream basic_unzip_streambuf::underflow

Summary A memory-safety vulnerability in Open Babel's bundled zipstream decompression code caused an out-of-bounds write via overlapping memcpy when reading a crafted gzip-compressed chemistry file. Details The flaw was in basicunzipstreambuf::underflow. The decompression buffer refill path invok...

PYSEC-2026-2785 Open Babel has out-of-bounds read in PQS lowerit (pre-buffer read)

Summary A memory-safety vulnerability in Open Babel's PQS parser caused an out-of-bounds pre-buffer read when reading a crafted input file. Details The flaw was in the lowerit helper used by the PQS parser. A malformed input caused the helper to read one or more bytes before the start of its inpu...

PYSEC-2026-2793 Open Babel has out-of-bounds write in Gaussian coords_type orientation parser

Summary A memory-safety vulnerability in Open Babel's Gaussian output parser allowed an out-of-bounds write when reading a crafted input file. Details The flaw was in the coordstype orientation parser inside the Gaussian output reader. A malformed orientation block caused the parser to write past...

PYSEC-2026-2772 Open Babel has NULL pointer dereference in CACAO CacaoFormat::SetHilderbrandt

Summary A memory-safety vulnerability in Open Babel's CACAO parser caused a NULL pointer dereference when reading a crafted input file. Details The flaw was in CacaoFormat::SetHilderbrandt. A malformed input caused the parser to dereference a NULL pointer while applying the Hilderbrandt...

PYSEC-2026-2782 Open Babel has NULL pointer dereference in ChemKinFormat::ReadReactionQualifierLines

Summary A memory-safety vulnerability in Open Babel's ChemKin parser caused a NULL pointer dereference when reading a crafted input file. Details The flaw was in ChemKinFormat::ReadReactionQualifierLines. A malformed reaction qualifier record caused the parser to dereference a NULL pointer. Impac...