CVE-2026-96749Heap out-of-bounds write via signed size overflow in BSON document encoding
Updated under an hour ago ()
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It affects MongoDB Python Driver. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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
- 8.4 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-190
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- mongodb
- NVD analysis
- Awaiting Analysis
- Record last updated
- Sep 26, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
MongoDB Python Driver mongodb:python_driver (from the name) | from 1.9.0 before 4.18.2 | CNA record |
References
- https://github.com/mongodb/mongo-python-driver/security/advisories/GHSA-v4x9-3549-crwv
- https://github.com/mongodb/mongo-python-driver/releases/tag/4.18.2
- https://github.com/mongodb/mongo-python-driver/blob/4.18.2/doc/changelog.rst
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.