CVE-2026-8201Network attack vector

Client query interruption via positional projection use-after-free

Published May 13, 2026 · Updated May 13, 2026

Use-after-free in MongoDB Server FLE query analysis allows attackers controlling a client query to interrupt its processing. The replaceEncryptedFieldsInFilter path processes a positional projection on an encrypted field, then accesses an object after its lifetime ends. Reachability requires mongocryptd or crypt_shared and control of an FLE query's structure; MongoDB has not specified whether the interruption is a crash or hang.

CVSS severity6.1
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in MongoDB Server FLE query analysis allows attackers controlling a client query to interrupt its processing. The replaceEncryptedFieldsInFilter path processes a positional projection on an encrypted field, then accesses an object after its lifetime ends. Reachability requires mongocryptd or crypt_shared and control of an FLE query's structure; MongoDB has not specified whether the interruption is a crash or hang.

The record

CVE
CVE-2026-8201
Published
May 13, 2026
Updated
May 13, 2026
Vendor
MongoDB
Product
MongoDB Server
Classifications
CWE-416, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 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=7.0 <7.0.34
  2. Affected versionversion=8.0 <8.0.23
  3. Affected versionversion=8.2 <8.2.9
  4. Affected versionversion=8.3 <8.3.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MongoDB · MongoDB Serverversion=7.0 <7.0.34; version=8.0 <8.0.23; version=8.2 <8.2.9; version=8.3 <8.3.2

Published CVSS scores

6.1MongoDB, Inc.CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:L/SI:N/SA:N
6.4MongoDB, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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