---
cve: "CVE-2026-9740"
severity: "HIGH"
cvss: 8.7
epss: "35%"
vendor: "MONGODB"
kev: false
exploited: false
published: "2026-06-09 23:17:03"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-10T12:13:03+02:00"
---

# CVE-2026-9740

> 8.7 HIGH

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- ef9b301aabaadf6850a065ac7fcd6b327be8c3c2 (Commit)
- d0ad95914a3351a12faf03ba35d41c43bc6feb7e (Commit)

## Referenzen

- <https://jira.mongodb.org/browse/SERVER-125063>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-9740) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_