High severity · published Jul 28, 2026
CVE-2026-59878
Apache ActiveMQ AMQP, Apache ActiveMQ, Apache ActiveMQ All: AMQP NIO negative frame size validation bypass leading to DoS
7.5
CVSS
0.8%
EPSS
No
On KEV
Description
Improper Input Validation vulnerability in Apache ActiveMQ AMQP, Apache ActiveMQ, Apache ActiveMQ All.
A remote unauthenticated peer that can reach an exposed AMQP NIO connector can trigger denial-of-service behavior by sending a frame size value. This cause the NIO threads to die and if done rapidly enough can lead to exhaustion of the NIO thread pool denying service to other connections.
This issue affects Apache ActiveMQ AMQP: before 5.19.9, from 6.0.0 before 6.2.8; Apache ActiveMQ: before 5.19.9, from 6.0.0 before 6.2.8; Apache ActiveMQ All: before 5.19.9, from 6.0.0 before 6.2.8.
Users are recommended to upgrade to version 5.19.9, 6.2.8, or 6.3.0 which fixes the issue.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 56% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AC
ActiveMQ · Apache
before 5.19.9; 6.0.0 before 6.2.8 · source: vendor, NVD
AA
Apache ActiveMQ AMQP · Apache Software Foundation
before 5.19.9; 6.0.0 before 6.2.8 · source: vendor
AA
Apache ActiveMQ All · Apache Software Foundation
before 5.19.9; 6.0.0 before 6.2.8 · source: vendor
AA
Activemq All · Apache
before 5.19.9; 6.0.0 before 6.2.8 · source: NVD
AA
Activemq Amqp · Apache
before 5.19.9; 6.0.0 before 6.2.8 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-59878
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-59878
Mailing List
https://lists.apache.org/thread/dnyx4d2oldshcj4lthso7b53y4bqmjvn
Mailing List
http://www.openwall.com/lists/oss-security/2026/07/27/7
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