OSV-2026-803 Container-overflow in OpenBabel::MDLFormat::ReadV3000Block

Not scored Published

A container overflow in OpenBabel's MDL format parser can cause a crash when processing malicious files, affecting applications using this library.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Not stated
Victim action needed
A user has to click or open something
Fix
None listed

What is OSV-2026-803?

OSV-2026-803 is a memory corruption vulnerability in openbabel, published on 24 May 2026.

Official description

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=515663946

Crash type: Container-overflow READ 1
Crash state:
OpenBabel::MDLFormat::ReadV3000Block
OpenBabel::MDLFormat::ReadMolecule
OpenBabel::OBConversion::Read

Which versions are affected by OSV-2026-803?

1 open source package ship an affected version, including openbabel.

PackageAffectedFixed in
openbabel OSS-FuzzAll versionsNone

How do I fix OSV-2026-803?

No fix has been published for OSV-2026-803 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is OSV-2026-803 being exploited?

There is no known exploitation of OSV-2026-803 in the wild and no public exploit code.

Sources

Is OSV-2026-803 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free