CVE-2026-82058: Unhandled Exception in MongoDB Server JSON Schema Validation Error Generation Leads to Denial of Service
A flaw in MongoDB's JSON Schema validation error generation code allows an authenticated user with readWrite privileges to crash the mongod server. When a BSON document containing an array with a malformed numeric field name fails a $jsonSchema items type constraint, the error generation path performs unsafe numeric conversion on the user-controlled field name without proper exception handling, resulting in an uncaught exception that terminates the server process. This is possible because incoming wire protocol BSON validation does not enforce that array element field names are valid, in-range numeric indices.
Affected Software
Event History
Frequently Asked Questions
Which users can trigger the server crash?
An authenticated user with readWrite privileges can trigger the condition. The vulnerability is reachable over MongoDB's wire protocol, so the attacker needs network access to the mongod server in addition to those privileges.
What input is required to exploit the issue?
The attacker must submit a BSON document containing an array whose numeric field name is malformed and causes the document to fail a $jsonSchema items type constraint. The failure must reach JSON Schema validation error generation, where the malformed field name is converted unsafely.
What is the operational impact of a successful exploit?
The malformed input causes an uncaught exception that terminates the mongod server process. The reported impact is denial of service; no confidentiality or integrity impact is indicated.