Medium severity · published Apr 7, 2026
CVE-2026-33227
Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ Web, Apache ActiveMQ: Improper Limitation of a Pathname to a Restricted Classpath Directory
4.3
CVSS
0.4%
EPSS
No
On KEV
Description
Improper validation and restriction of a classpath path name vulnerability in
Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ Web, Apache ActiveMQ.
In two instances (when creating a Stomp consumer and also browsing messages in the Web console) an authenticated user provided "key" value could be constructed to traverse the classpath due to path concatenation. As a result, the application is exposed to a classpath path resource loading vulnerability that could potentially be chained together with another attack to lead to exploit.
This issue affects Apache ActiveMQ Client: before 5.19.3, from 6.0.0 before 6.2.2; Apache ActiveMQ Broker: before 5.19.3, from 6.0.0 before 6.2.2; Apache ActiveMQ All: before 5.19.3, from 6.0.0 before 6.2.2; Apache ActiveMQ Web: before 5.19.3, from 6.0.0 before 6.2.2; Apache ActiveMQ: before 5.19.3, from 6.0.0 before 6.2.2.
Users are recommended to upgrade to version 5.19.4 or 6.2.3, which fixes the issue. Note: 5.19.3 and 6.2.2 also fix this issue, but that is limited to non-Windows environments due to a path separator resolution bug fixed in 5.19.4 and 6.2.3.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AC
ActiveMQ · Apache
before 5.19.3; 6.0.0 before 6.2.2 · source: vendor, NVD
AA
Apache ActiveMQ All · Apache Software Foundation
before 5.19.3; 6.0.0 before 6.2.2 · source: vendor
AA
Apache ActiveMQ Broker · Apache Software Foundation
before 5.19.3; 6.0.0 before 6.2.2 · source: vendor
AA
Apache ActiveMQ Client · Apache Software Foundation
before 5.19.3; 6.0.0 before 6.2.2 · source: vendor
AA
Apache ActiveMQ Web · Apache Software Foundation
before 5.19.3; 6.0.0 before 6.2.2 · source: vendor
AB
Activemq Broker · Apache
before 5.19.3; 6.0.0 before 6.2.2 · source: NVD
AW
Activemq Web · Apache
before 5.19.3; 6.0.0 before 6.2.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33227
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-33227
Vendor Advisory
https://activemq.apache.org/security-advisories.data/CVE-2026-33227-announcement.txt
Mailing List
http://www.openwall.com/lists/oss-security/2026/04/06/4
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