{"cve":"CVE-2026-96749","nvd":{"published":"2026-09-24T19:17:20.963","modified":"2026-09-26T04:17:52.260","status":"Undergoing Analysis","description":"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.","cvss_v4":{"vector":"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","score":7.5},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.4},"cwes":["CWE-190"],"references":["https://github.com/mongodb/mongo-python-driver/blob/4.18.2/doc/changelog.rst","https://github.com/mongodb/mongo-python-driver/releases/tag/4.18.2","https://github.com/mongodb/mongo-python-driver/security/advisories/GHSA-v4x9-3549-crwv"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-96749","score":0.00188,"percentile":0.08434,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-v4x9-3549-crwv","url":"https://osv.dev/vulnerability/GHSA-v4x9-3549-crwv","summary":"PyMongo: PYTHON-5996 Heap out-of-bounds write via signed size overflow in BSON document encoding","modified":"2026-10-15T14:56:20.520518785Z","packages":[{"ecosystem":"PyPI","name":"pymongo","purl":"pkg:pypi/pymongo","ranges":["<4.18.2"],"fixed":["4.18.2"]}]},{"id":"PYSEC-2026-4296","url":"https://osv.dev/vulnerability/PYSEC-2026-4296","summary":"PyMongo: PYTHON-5996 Heap out-of-bounds write via signed size overflow in BSON document encoding","modified":"2026-10-15T14:45:13.512676859Z","packages":[{"ecosystem":"PyPI","name":"pymongo","purl":"pkg:pypi/pymongo","ranges":["<4.18.2"],"fixed":["4.18.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}