An integer overflow in the BSON document encoding component of the MongoDB Python Driver's bundled native extension may occur when a single…
CVE-2026-96749
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.
Assessment
- CVSS
- 7.5 (v4.0)
- Severity
- High
- EPSS
- 0.19% chance of exploitation in the next 30 days
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 24 September 2026
- Last updated
- 5 October 2026
- Affected
- MONGODB · Python Driver · pymongo
- Weakness
- CWE-190
- Assigner
- cna@mongodb.com
CVSS vectorCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
At the source
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
- https://nvd.nist.gov/vuln/detail/CVE-2026-96749
- https://github.com/mongodb/mongo-python-driver/pull/3066
- https://github.com/mongodb/mongo-python-driver/commit/640dd2383a1a2fb1a10e5222d50ebc0b22a61bd7
- https://github.com/mongodb/mongo-python-driver/commit/6ab44be0e97c9d1d5a23725c4978fb25f3249485
- https://www.mongodb.com/community/forums/t/pymongo-4-18-2-released/343732
- https://github.com/advisories/GHSA-v4x9-3549-crwv
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