CVE-2026-81524Network attack vector

Data access and modification via namespace injection

Published Aug 27, 2026 · Updated Aug 27, 2026

Resource injection in MongoDB C Driver before 2.5.1 allows remote authenticated users to access or modify unintended data resources. libmongoc composes database and collection namespaces without rejecting periods in database names or NUL bytes in either name, so encoding can silently retarget an operation. Exploitation requires an application to place untrusted input into those name components; consequences are limited to data reachable through the application's MongoDB privileges.

CVSS severity5.4
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource injection in MongoDB C Driver before 2.5.1 allows remote authenticated users to access or modify unintended data resources. libmongoc composes database and collection namespaces without rejecting periods in database names or NUL bytes in either name, so encoding can silently retarget an operation. Exploitation requires an application to place untrusted input into those name components; consequences are limited to data reachable through the application's MongoDB privileges.

The record

CVE
CVE-2026-81524
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
MongoDB
Product
MongoDB .NET/C# Driver
Classifications
CWE-99, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 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=1.0.0 <2.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MongoDB · MongoDB .NET/C# Driverversion=1.0.0 <2.5.1

Published CVSS scores

5.3UbuntuCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
5.4MongoDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A: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.

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-99Improper Control of Resource Identifiers ('Resource Injection')
T1565.001Stored Data Manipulation

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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