CVE-2026-4148Network attack vector

Authenticated memory corruption via ExpressionContext use-after-free

Published Mar 17, 2026 · Updated Mar 17, 2026

Use-after-free in MongoDB Server 7.0 before 7.0.31, 8.0 before 8.0.20, and 8.2 before 8.2.6 allows remote authenticated users to corrupt memory. The classic query engine releases an ExpressionContext while crafted $lookup or $graphLookup processing still uses it; MongoDB has not disclosed the exact lifetime error. The path requires a sharded cluster and read-role credentials; the vendor has not published a more specific operational consequence.

CVSS severity8.7
High
EPSS probability0.32%
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 7.0 before 7.0.31, 8.0 before 8.0.20, and 8.2 before 8.2.6 allows remote authenticated users to corrupt memory. The classic query engine releases an ExpressionContext while crafted $lookup or $graphLookup processing still uses it; MongoDB has not disclosed the exact lifetime error. The path requires a sharded cluster and read-role credentials; the vendor has not published a more specific operational consequence.

The record

CVE
CVE-2026-4148
Published
Mar 17, 2026
Updated
Mar 17, 2026
Vendor
MongoDB
Product
MongoDB Server
Classifications
CWE-416
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 17, 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 <7.0.31
  2. Affected versionversion=8.0 <8.0.20
  3. Affected versionversion=8.2 <8.2.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MongoDB · MongoDB Serverversion=7.0 <7.0.31; version=8.0 <8.0.20; version=8.2 <8.2.6

Published CVSS scores

8.7MongoDB, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.8MongoDB, Inc.CVSS: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

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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