{"id":"GHSA-v4x9-3549-crwv","summary":"PyMongo: PYTHON-5996 Heap out-of-bounds write via signed size overflow in BSON document encoding","details":"An integer overflow in the BSON document encoding component of the MongoDB Python Driver's bundled native extension may occur when a single document is built from an unusually large amount of caller-supplied data. Size arithmetic is performed in a signed 32-bit type, and the guard meant to catch the overflow is written in a form whose behavior is not defined by the C language standard. A party with no privileges who can place a very large value into data that an application encodes may, depending on how the native extension was built, cause a write outside the bounds of an allocated buffer inside the application's own process.","aliases":["CVE-2026-96749"],"modified":"2026-10-06T00:00:11.931260707Z","published":"2026-10-05T23:47:10Z","database_specific":{"github_reviewed_at":"2026-10-05T23:47:10Z","nvd_published_at":"2026-09-24T19:17:20Z","cwe_ids":["CWE-190"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/mongodb/mongo-python-driver/security/advisories/GHSA-v4x9-3549-crwv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-96749"},{"type":"WEB","url":"https://github.com/mongodb/mongo-python-driver/pull/3066"},{"type":"WEB","url":"https://github.com/mongodb/mongo-python-driver/commit/640dd2383a1a2fb1a10e5222d50ebc0b22a61bd7"},{"type":"WEB","url":"https://github.com/mongodb/mongo-python-driver/commit/6ab44be0e97c9d1d5a23725c4978fb25f3249485"},{"type":"PACKAGE","url":"https://github.com/mongodb/mongo-python-driver"},{"type":"WEB","url":"https://github.com/mongodb/mongo-python-driver/blob/4.18.2/doc/changelog.rst"},{"type":"WEB","url":"https://github.com/mongodb/mongo-python-driver/releases/tag/4.18.2"},{"type":"WEB","url":"https://www.mongodb.com/community/forums/t/pymongo-4-18-2-released/343732"}],"affected":[{"package":{"name":"pymongo","ecosystem":"PyPI","purl":"pkg:pypi/pymongo"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.18.2"}]}],"versions":["0.1.1pre","0.1.2pre","0.10","0.10.1","0.10.2","0.10.3","0.11","0.11.1","0.11.2","0.11.3","0.12","0.13","0.14","0.14.1","0.14.2","0.15","0.15.1","0.15.2","0.16","0.1pre","0.2pre","0.3.1pre","0.3pre","0.4pre","0.5.1pre","0.5.2pre","0.5.3pre","0.5pre","0.6","0.7","0.7.1","0.7.2","0.8","0.8.1","0.9","0.9.1","0.9.2","0.9.3","0.9.4","0.9.5","0.9.6","0.9.7","1.0","1.1","1.1.1","1.1.2","1.10","1.10.1","1.11","1.2","1.2.1","1.3","1.4","1.5","1.5.1","1.5.2","1.6","1.7","1.8","1.8.1","1.9","2.0","2.0.1","2.1","2.1.1","2.2","2.2.1","2.3","2.4","2.4.1","2.4.2","2.5","2.5.1","2.5.2","2.6","2.6.1","2.6.2","2.6.3","2.7","2.7.1","2.7.2","2.8","2.8.1","2.9","2.9.1","2.9.2","2.9.3","2.9.4","2.9.5","3.0","3.0.1","3.0.2","3.0.3","3.1","3.1.1","3.10.0","3.10.1","3.11.0","3.11.1","3.11.2","3.11.3","3.11.4","3.12.0","3.12.1","3.12.2","3.12.3","3.13.0","3.2","3.2.1","3.2.2","3.3.0","3.3.1","3.4.0","3.5.0","3.5.1","3.6.0","3.6.1","3.7.0","3.7.1","3.7.2","3.8.0","3.9.0","4.0","4.0.1","4.0.2","4.1.0","4.1.1","4.10.0","4.10.1","4.11","4.11.1","4.11.2","4.11.3","4.12.0","4.12.1","4.13.0","4.13.0.dev0","4.13.1","4.13.2","4.14.0","4.14.1","4.15.0","4.15.1","4.15.2","4.15.3","4.15.4","4.15.5","4.16.0","4.16.0.dev0","4.17.0","4.18.0","4.18.1","4.2.0","4.3.2","4.3.3","4.4.0","4.4.0b0","4.4.1","4.5.0","4.6.0","4.6.1","4.6.2","4.6.3","4.7.0","4.7.1","4.7.2","4.7.3","4.8.0","4.8.0b0","4.9","4.9.1","4.9.2"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-v4x9-3549-crwv/GHSA-v4x9-3549-crwv.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}