CVE-2026-106435
Medium
Description
The MongoDB Python Driver's binary accelerator can read outside a buffer when an application decodes malformed BSON containing a truncated regular-expression element without a trailing NUL byte. An actor who can supply BSON to the documented decode or decode_all API can cause the application process to terminate when the C extension is loaded. The driver's normal database wire-protocol path does not reach this code.
SeverityMedium
CVSS5.1
Exploit probability—
Product
Mongodb Python Driver
PublishedOct 8, 2026
First seenOct 8, 2026
Weakness typeCWE-125Out-of-bounds read
How to fix
Update
- mongodb python_driver4.18.3 or later
- pymongo4.18.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mongodb python_driver | v < 4.18.3 | 4.18.3 |
| pymongoPyPI | 3.9.0 ≤ v < 4.18.3 | 4.18.3 |
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