Heap out-of-bounds write via signed size overflow in BSON document encoding (MongoDB Python Driver)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.19 % · percentile 8 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- mongodb
- NVD status
- Awaiting 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.
Weaknesses (CWE)
- CWE-190 — Integer Overflow or Wraparound
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | HIGH 7.5 | 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 | mongodb |
| CVSS 3.1 | HIGH 8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | mongodb |
| CVSS 4.0 | HIGH 7.5 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · cna@mongodb.com (Secondary) |
| CVSS 3.1 | HIGH 8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | NVD · cna@mongodb.com (Secondary) |
Advisories
- GHSA-v4x9-3549-crwv — PyMongo: PYTHON-5996 Heap out-of-bounds write via signed size overflow in BSON document encoding
- PYSEC-2026-4296 — PyMongo: PYTHON-5996 Heap out-of-bounds write via signed size overflow in BSON document encoding
European references
- ENISA EUVD · EUVD-2026-86348
- GCVE · GCVE-0-2026-96749
CERT-FR advisories
- CERTFR-2026-AVI-1234 — Multiples vulnérabilités dans MongoDB · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| MongoDB · Python Driver | affected 1.9.0 < 4.18.2 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |