Use-After-Free Vulnerability in MongoDB Server's Replication Component
CVE-2026-118383

9.5CRITICAL

Key Information:

Vendor

Mongodb
Status
Mongodb Server
Vendor
CVE Published:
10 November 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-118383?

A use-after-free vulnerability exists in the replication component of MongoDB Server, leading to potential server crashes or, in certain situations, arbitrary code execution. This issue can be triggered during the catch-up process of a newly elected primary in a replica set when authentication is not required for some requests. Affected components include replica set members, shard, and config server replica set members in sharded clusters, while standalone mongod instances remain unaffected. Proper configurations and updates are essential to mitigate this risk.

Affected Version(s)

MongoDB Server 9.0.0 < 9.0.7

MongoDB Server 8.3.0 < 8.3.16

MongoDB Server 8.0.0 < 8.0.37

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-118383
Created by googlesky

References

https://jira.mongodb.org/browse/SERVER-138119
https://jira.mongodb.org/browse/SERVER-138175

CVSS V4

Score:
9.5
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

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