{"id":"CVE-2026-3408","aliases":["GHSA-rxpr-wq63-jr7p","PYSEC-2026-2791"],"url":"https://o3.security/vulnerability/CVE-2026-3408","summary":"Open Babel CDXML File atom.cpp GetExplicitValence null pointer dereference","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.","published":"2026-03-02T03:32:10.760Z","modified":"2026-10-21T09:54:40.992100141Z","cvss":null,"epss":{"score":0.00489,"percentile":0.40327,"asOf":"2026-09-07"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"openbabel","fixedVersion":"3.2.0"}],"fix":{"url":"https://github.com/VedantMadane/openbabel/commit/e23a224b8fd9d7c2a7cde9ef4ec6afb4c05aa08a","label":"VedantMadane/openbabel@e23a224"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3408.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-3408"},{"type":"ADVISORY","url":"https://vuldb.com/?id.348303"},{"type":"ADVISORY","url":"https://vuldb.com/?submit.763756"},{"type":"REPORT","url":"https://github.com/openbabel/openbabel/issues/2848"},{"type":"REPORT","url":"https://vuldb.com/?ctiid.348303"},{"type":"FIX","url":"https://github.com/VedantMadane/openbabel/commit/e23a224b8fd9d7c2a7cde9ef4ec6afb4c05aa08a"},{"type":"FIX","url":"https://github.com/openbabel/openbabel/pull/2862"},{"type":"EVIDENCE","url":"https://github.com/oneafter/0128/blob/main/ob3/repro.cdxml"},{"type":"WEB","url":"https://github.com/openbabel/openbabel/security/advisories/GHSA-rxpr-wq63-jr7p"},{"type":"PACKAGE","url":"https://github.com/openbabel/openbabel"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T09:54:40.992100141Z"}}