CVE-2026-106433

Heap corruption via duplicate masterKey fields in MongoDB libmongocrypt

HIGH
8.8
CVSS Score
Published: October 8, 2026 at 06:55 PM UTC
Updated: October 27, 2026 at 08:17 PM UTC
1 product affected across 1 vendorLibmongocrypt

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Severity
HIGH8.8
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

Improper state management in MongoDB libmongocrypt can cause provider-specific data to be treated as an incompatible type when cleaning up a key document containing duplicate masterKey fields. An authenticated actor who can modify key vault documents, or a server that returns such a key document, can cause invalid memory access and invalid frees in the client process. This can terminate the application or corrupt process memory.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

1.5.0 ≤ v < 1.20.51.1.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

Vendor AdvisoryIssue Tracking
Source: cverecord
https://jira.mongodb.org/browse/MONGOCRYPT-964

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHmongodb
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-843

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