CVE-2026-53917: Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ, Apache ActiveMQ All, Apache Acti

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HIGH 7.5REMOTEWATCHLISTUPGRADEUPGRADE

CVE-2026-53917 is a high-severity flaw (CVSS 7.5) affecting activemq, activemq broker. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ Client, Apache ActiveMQ Broker. An authenticated user can cause a broker DoS by sending a crafted OpenWire Message with a large encoded size value for the map. OpenWire message property maps are unmarshaled without size validation which can trigger OOM and crash the broker. This issue affects Apache ActiveMQ: before 5.19.8, from 6.0

Why this priority

High severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 46%)
CISA exploited list	No
Weakness	CWE-789
Published	2026-06-30
Last modified	2026-07-02

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-07-02 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-30 11:16 UTCPublished CVE record published
2026-07-02 18:41 UTCUpdated Record last modified

apache activemq UPGRADE

Affected: < 5.19.8 · >= 6.0.0 and < 6.2.7

Fixed in: 5.19.8, 6.2.7

Safe to downgrade to: a release before 6.0.0

1. Check installed version

apt-cache policy activemq || rpm -q activemq || activemq --version

2. UPGRADE to 5.19.8 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade activemq

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade activemq

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 6.0.0 (Debian / Ubuntu)

apt-cache madison activemq sudo apt install activemq=<VERSION_BEFORE_6.0.0> sudo apt-mark hold activemq

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list activemq sudo dnf downgrade activemq-<VERSION_BEFORE_6.0.0> sudo dnf versionlock add activemq

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

apache activemq broker UPGRADE

Affected: < 5.19.8 · >= 6.0.0 and < 6.2.7

Fixed in: 5.19.8, 6.2.7

Safe to downgrade to: a release before 6.0.0

1. Check installed version

apt-cache policy activemq-broker || rpm -q activemq-broker || activemq-broker --version

2. UPGRADE to 5.19.8 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade activemq-broker

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade activemq-broker

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 6.0.0 (Debian / Ubuntu)

apt-cache madison activemq-broker sudo apt install activemq-broker=<VERSION_BEFORE_6.0.0> sudo apt-mark hold activemq-broker

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list activemq-broker sudo dnf downgrade activemq-broker-<VERSION_BEFORE_6.0.0> sudo dnf versionlock add activemq-broker

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-53917?

activemq: upgrade to 5.19.8, 6.2.7; activemq broker: upgrade to 5.19.8, 6.2.7. Exact commands for each OS are on this page.

Is CVE-2026-53917 being exploited?

CVE-2026-53917 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-53917 affect?

CVE-2026-53917 affects activemq, activemq broker. Severity is high (CVSS 7.5). Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ Client, Apache ActiveMQ Broker. An authenticated user can cause a broker DoS by sending a crafted OpenWire Message with a la

How urgent is CVE-2026-53917?

Priority 50/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Apache ActiveMQ vulnerabilities

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References

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