Vulnerability · Published Jun 9, 2026 · Assigned by mongodb
CVE-2026-9740Unbounded recursion in BSONColumn interleaved-reference causes pre-auth stack overflow
High 7.5
In plain English
A high-severity security flaw in MongoDB Server from MongoDB. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.3%top 71.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A vulnerability in MongoDB Server's BSON validation logic allows an unauthenticated user to crash the mongod process by sending a specially crafted message. The BSON validator's handling of certain nested binary data structures permits uncontrolled mutual recursion between validation functions, where each re-entry resets internal depth tracking.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| MongoDB | MongoDB Server | 8.3.0 – before 8.3.38.2.0 – before 8.2.108.0.0 – before 8.0.247.0.0 – before 7.0.35 |
Weakness: CWE-674 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H