CVE-2026-18711Network attack vectorHinoki check available

Authenticated crash and disclosure via Decimal128 use-after-free

Published Aug 11, 2026 · Updated Aug 11, 2026

Use-after-free in MongoDB Server 8.0 before 8.0.29 and 8.3.0 through 8.3.7 allows remote authenticated users to crash mongod. The query executor fails to treat Decimal128 values as potentially invalid while preparing a cursor to yield or detach, leaving an internal reference live after its backing memory is freed. Read and write privileges and certain queries against time-series collections are required; exploitation crashes the server or returns freed-memory contents in query results.

CVSS severity7.1
High
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
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Summary

What happened

Use-after-free in MongoDB Server 8.0 before 8.0.29 and 8.3.0 through 8.3.7 allows remote authenticated users to crash mongod. The query executor fails to treat Decimal128 values as potentially invalid while preparing a cursor to yield or detach, leaving an internal reference live after its backing memory is freed. Read and write privileges and certain queries against time-series collections are required; exploitation crashes the server or returns freed-memory contents in query results.

The record

CVE
CVE-2026-18711
Published
Aug 11, 2026
Updated
Aug 11, 2026
Vendor
MongoDB
Product
MongoDB Server
Classifications
CWE-416, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=8.0 <8.0.29
  2. Affected versionversion=8.3.0 <8.3.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MongoDB · MongoDB Serverversion=8.0 <8.0.29; version=8.3.0 <8.3.8

Published CVSS scores

7.1MongoDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H
7.1MongoDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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