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 internal buffer while formatting the description.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 CIF file with the
obabeltool, the OBConversion API, or any of the language bindings.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/e23a224b Tracked in #2862.
A minimized reproducer for this CVE is checked in at
test/files/fuzz_regress/cve-2026-2704.cifand is exercised on every CI build under ASAN+UBSAN by thefuzzregresstestharness.Credit
Reported by Vedant Madane (@VedantMadane).
3.2.0Exploitability
AV:NAC:LAT:NPR:NUI:PVulnerable System
VC:NVI:NVA:LSubsequent System
SC:NSI:NSA:N2.1/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P