GHSA-55f6-pf8r-c2f4
HIGHOpen Babel has out-of-bounds write in MOPAC translationVectors[] (UNIT CELL TRANSLATION)
Blast Radius
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Description
Summary
A memory-safety vulnerability in Open Babel's MOPAC output parser
allowed an out-of-bounds write into the translationVectors[] array
when reading the "UNIT CELL TRANSLATION" block of a crafted input
file.
Details
The MOPAC output reader stored translation vectors from the UNIT CELL
TRANSLATION block into a fixed-size translationVectors[] array. A
malformed block could push more vectors than the array had slots,
causing a write past the end of the array. One of five
translationVectors[] OOB writes in the TALOS 2022 batch.
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 MOPAC output 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/40e85213
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | openbabel | all versions | 3.2.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openbabel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update openbabel to 3.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-55f6-pf8r-c2f4 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-55f6-pf8r-c2f4 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-55f6-pf8r-c2f4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-55f6-pf8r-c2f4 in your dependencies?
O3 detects GHSA-55f6-pf8r-c2f4 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.