CVE-2021-26117Network attack vector

Authentication bypass via anonymous LDAP bind

Published Jan 27, 2021 · Updated Aug 3, 2024

Improper authentication in Apache ActiveMQ before 5.16.1 allows remote attackers to bypass LDAP password checks via anonymous bind. The optional LDAP login module reuses an anonymous LDAP context to verify a supplied password, so the password is not checked. The flaw requires anonymous LDAP access to be enabled and can grant broker authentication without valid credentials; the record reports integrity impact without confidentiality or availability impact.

CVSS severity7.5
High
EPSS probability11.33%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Apache ActiveMQ before 5.16.1 allows remote attackers to bypass LDAP password checks via anonymous bind. The optional LDAP login module reuses an anonymous LDAP context to verify a supplied password, so the password is not checked. The flaw requires anonymous LDAP access to be enabled and can grant broker authentication without valid credentials; the record reports integrity impact without confidentiality or availability impact.

The record

CVE
CVE-2021-26117
Published
Jan 27, 2021
Updated
Aug 3, 2024
Vendor
The Apache Software Foundation
Product
Apache ActiveMQ
Classifications
CWE-287, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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=Apache ActiveMQ <5.16.1 changes=[{"at":"5.15.14","status":"unaffected"}]
  2. Affected versionversion=Apache ActiveMQ Artemis <2.16.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache ActiveMQversion=Apache ActiveMQ <5.16.1 changes=[{"at":"5.15.14","status":"unaffected"}]; version=Apache ActiveMQ Artemis <2.16.0

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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.

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No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1190Exploit Public-Facing Application

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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