{"id":"PYSEC-2026-2791","summary":"Open Babel has a NULL pointer dereference in CDXML OBAtom::GetExplicitValence","details":"### Summary\n\nA memory-safety vulnerability in Open Babel's CDXML file format parser\ncaused a NULL pointer dereference when reading a crafted input file.\n\n### Details\n\nThe flaw was in `OBAtom::GetExplicitValence` as called from the CDXML\nparser. A malformed fragment caused the parser to invoke the method\non a NULL atom pointer.\n\n### Impact\n\nOpen Babel is a C++ library and CLI used to read and write chemistry\nfile formats; it is shipped by Linux distributions and embedded in\nservices that may parse untrusted input. Triggering this vulnerability\nrequires the victim to open a malicious CDXML file with the `obabel`\ntool, the `OBConversion` API, or any of the language bindings (Python,\nRuby, Java, R, Perl, C#, PHP).\n\n### Affected versions\n\nAll releases up to and including 3.1.1.\n\n### Patched version\n\n3.2.0 (released 2026-05-26).\n\n### Patch\n\nFix commit: https://github.com/openbabel/openbabel/commit/e23a224b\nTracked in #2862.\n\nA minimized reproducer for this CVE is checked in under\n`test/files/fuzz_regress/` and is exercised on every CI build under\nASAN+UBSAN by the `fuzzregresstest` harness.\n\n### Credit\n\nReported by Vedant Madane (@VedantMadane) via VulDB.","aliases":["CVE-2026-3408","GHSA-rxpr-wq63-jr7p"],"modified":"2026-07-13T16:32:26.300440085Z","published":"2026-07-13T15:46:25.400561Z","references":[{"type":"WEB","url":"https://github.com/openbabel/openbabel/security/advisories/GHSA-rxpr-wq63-jr7p"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-3408"},{"type":"WEB","url":"https://github.com/openbabel/openbabel/issues/2848"},{"type":"WEB","url":"https://github.com/openbabel/openbabel/pull/2862"},{"type":"WEB","url":"https://github.com/VedantMadane/openbabel/commit/e23a224b8fd9d7c2a7cde9ef4ec6afb4c05aa08a"},{"type":"WEB","url":"https://github.com/oneafter/0128/blob/main/ob3/repro.cdxml"},{"type":"PACKAGE","url":"https://github.com/openbabel/openbabel"},{"type":"WEB","url":"https://vuldb.com/?ctiid.348303"},{"type":"WEB","url":"https://vuldb.com/?id.348303"},{"type":"WEB","url":"https://vuldb.com/?submit.763756"},{"type":"PACKAGE","url":"https://pypi.org/project/openbabel"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-rxpr-wq63-jr7p"}],"affected":[{"package":{"name":"openbabel","ecosystem":"PyPI","purl":"pkg:pypi/openbabel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.2.0"}]}],"versions":["1.8","1.8.1","1.8.2","1.8.3","1.8.4","2.4.0","2.4.1","3.0.0","3.0.0a1","3.1.1","3.1.1.1"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/openbabel/PYSEC-2026-2791.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"},{"type":"CVSS_V4","score":"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"}]}