Out-of-bounds Read in MongoDB Python Driver
CVE-2026-106435
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.1 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-106435?
- CVE-2026-106435 is a medium-severity vulnerability in MongoDB Python Driver, classified under Out-of-bounds Read. CVSS score: 5.1/10. Published 2026-10-08.
- How severe is CVE-2026-106435?
- Medium severity. CVSS v3 base score is 5.1 out of 10.