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CVE-2025-27533 Apache ActiveMQ

Affected softwareApache ActiveMQ
Severity6.9 Medium CVSS 4.0 2 scores
Fixed in5.16.8, 5.17.7, 5.18.7, 6.1.6
WeaknessCWE-789
Published7 May 2025
Updated17 Jun 2026

Description

Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ. During unmarshalling of OpenWire commands the size value of buffers was not properly validated which could lead to excessive memory allocation and be exploited to cause a denial of service (DoS) by depleting process memory, thereby affecting applications and services that rely on the availability of the ActiveMQ broker when not using mutual TLS connections. This issue affects Apache ActiveMQ: from 6.0.0 before 6.1.6, from 5.18.0 before 5.18.7, from 5.17.0 before 5.17.7, before 5.16.8. ActiveMQ 5.19.0 is not affected. Users are recommended to upgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7, or 5.16.8 or which fixes the issue. Existing users may implement mutual TLS to mitigate the risk on affected brokers.

Exploitation status

Working exploit published

A reviewed exploit catalogue lists ready-to-run exploit code for this CVE.

  • CISA KEV not listed
  • VulnCheck KEV not listed
  • CISA Vulnrichment exploitation: none
  • Indexed PoC 2 indexed Published artifacts you can open, in Exploit-DB, GitHub PoC; first seen 2025-05-09.
  • EPSS 9.1% chance in 30 days
IndexArtifactStarsFirst seen
GitHub PoC exploit for CVE-2025-27533, a Denial of Service (DoS) vulnerability in Apache ActiveMQ 8 2025-05-09
Exploit-DB Apache ActiveMQ 6.1.6 - Denial of Service (DOS) 2025-05-09

Waratek protection

Mitigation candidate

A kind of vulnerability Waratek's rules address, with exploit code published or exploitation reported. No rule exists and none is planned yet. The decision below says what we found to build a rule from.

  • Protection none
  • Action unverified
  • Review automated Inferred
  • Record active
Decided by The affected package being open source on Maven, so the fix can be read
Finding This CVE affects an open-source Java library published on Maven Central (Maven packages: org.apache.activemq:activemq-openwire-legacy, org.apache.activemq:activemq-client), so it is squarely in ARMR's territory and the source needed to understand the defect is public. That makes it a candidate for an ARMR patch rule. No rule exists and none is scheduled: the diff between the affected and fixed versions has not been read, and a closer look may find no hook point ARMR can act on.

CVSS

6.9 MEDIUM v4.0 CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:D/RE:M/U:Red 2 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

VersionScoreBandVectorAssignerType
CVSS 4.0 6.9 MEDIUM CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:D/RE:M/U:Red security@apache.org Secondary published
CVSS 3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H NVD Primary

Affected software and releases

Oracle advisories

AdvisoryTypeQuarterProducts Oracle names in its risk matrix
Oracle Critical Patch Update January 2026 ↗ CPU 2026-Q1 Oracle Communications / Third Party (Apache ActiveMQ) (9.0.0-9.0.4)
Oracle Communications / Third Party (Apache ActiveMQ) (9.0.0-9.0.4)
Oracle Critical Patch Update October 2025 ↗ CPU 2025-Q4 Oracle Communications Applications / Core (Apache ActiveMQ) (6.1.0-6.1.1)
Oracle Fusion Middleware / General (Apache ActiveMQ) (12.2.1.4.0, 14.1.2.0.0)
Oracle Critical Patch Update July 2025 ↗ CPU 2025-Q3 Oracle Communications Applications / Microservices (Apache ActiveMQ) (6.0.5-6.1.0)
Oracle Financial Services Applications / Platform (Apache ActiveMQ) (8.0.7.8, 8.0.8.6, 8.1.1.4, 8.1.2.5)

Oracle components and versions

FamilyComponentVersions, as Oracle lists themRead as
Oracle Communications Third Party (Apache ActiveMQ) 9.0.0-9.0.4
Oracle Communications Applications Core (Apache ActiveMQ) 6.1.0-6.1.1
Oracle Communications Applications Microservices (Apache ActiveMQ) 6.0.5-6.1.0
Oracle Financial Services Applications Platform (Apache ActiveMQ) 8.0.7.8, 8.0.8.6, 8.1.1.4, 8.1.2.5 8.0.7.8 · 8.0.8.6 · 8.1.1.4 · 8.1.2.5
Oracle Fusion Middleware General (Apache ActiveMQ) 12.2.1.4.0, 14.1.2.0.0 12.2.1.4.0 · 14.1.2.0.0

Maven packages

Affected and fixed versions, from OSV.dev
PackageIntroducedFixedLast affected
org.apache.activemq:activemq-openwire-legacy 0 5.16.8 unbounded
org.apache.activemq:activemq-client 0 5.16.8 unbounded
org.apache.activemq:activemq-openwire-legacy 5.17.0 5.17.7 unbounded
org.apache.activemq:activemq-openwire-legacy 5.18.0 5.18.7 unbounded
org.apache.activemq:activemq-openwire-legacy 6.0.0 6.1.6 unbounded
org.apache.activemq:activemq-client 5.17.0 5.17.7 unbounded
org.apache.activemq:activemq-client 5.18.0 5.18.7 unbounded
org.apache.activemq:activemq-client 6.0.0 6.1.6 unbounded

Products and versions

3 products, 12 version entries
SourceVendorProductSchemeAffected versions
nvd apache activemq generic ≥ 5.16.0 and < 5.16.8 · ≥ 5.17.0 and < 5.17.7 · ≥ 5.18.0 and < 5.18.7 · ≥ 6.0.0 and < 6.1.6
osv org.apache.activemq activemq-client generic < 5.16.8 · ≥ 5.17.0 and < 5.17.7 · ≥ 5.18.0 and < 5.18.7 · ≥ 6.0.0 and < 6.1.6
osv org.apache.activemq activemq-openwire-legacy generic < 5.16.8 · ≥ 5.17.0 and < 5.17.7 · ≥ 5.18.0 and < 5.18.7 · ≥ 6.0.0 and < 6.1.6

References

URLTags
https://github.com/apache/activemq/commit/fc4372b9f0f72b8b5eed917f0019c5cea45c5d06 WEB
https://github.com/apache/activemq PACKAGE
https://issues.apache.org/jira/browse/AMQ-6596 WEB
https://lists.apache.org/thread/8hcm25vf7mchg4zbbhnlx2lc5bs705hg WEB
https://lists.debian.org/debian-lts-announce/2025/06/msg00020.html WEB
http://www.openwall.com/lists/oss-security/2025/05/06/1 WEB

Timeline

Published2025-05-07By the CVE Program.
NVD record modified2026-06-17NVD's own last-modified date for this record.