CVE-2026-106435

Application denial of service via out-of-bounds read in BSON Regex decoding in MongoDB Python Driver

Published Oct 8, 2026 CVSS 4.0 · 5.9 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-98qm-wvgf-w4cf MongoDB Python Driver: Out-of-bounds read in BSON decoding via a malformed Regex element
History
Type Values Removed Values Added
CPEs cpe:2.3:a:mongodb:python_driver:*:*:*:*:*:mongodb:*:*
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mongodb
Mongodb python Driver
Vendors & Products Mongodb
Mongodb python Driver
Type Values Removed Values Added
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.
Title Application denial of service via out-of-bounds read in BSON Regex decoding in MongoDB Python Driver
Weaknesses CWE-125
References
Metrics cvssV3_1

{'score': 5.1, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 5.9, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mongodb
Published
Updated
Oct 9, 2026, 11:49 AM
Reserved
Oct 6, 2026, 4:40 PM
Status
Analyzed
Published
Oct 8, 2026, 9:17 PM
Modified
Oct 15, 2026, 5:00 PM
Severity
Moderate
Public date
Oct 8, 2026, 8:12 PM