CVE-2026-42253: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Apache A

This month

MEDIUM 6.1WATCHLISTUPGRADEUPGRADE

CVE-2026-42253 is a medium-severity flaw (CVSS 6.1) affecting activemq, activemq web. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Apache ActiveMQ, Apache ActiveMQ Web. The MessageServlet in the ActiveMQ web console API copies every JMS message property into an HTTP response header without any validation. This can allow overwriting and injecting security headers by setting them on JMS messages that are returned by the servlet. This issue affects Apache ActiveMQ: before 5.1

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.1% (top 34%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-06-01
Last modified	2026-07-22

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

Last updated 2026-07-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-01 09:16 UTCPublished CVE record published
2026-07-22 07:10 UTCUpdated Record last modified

apache activemq UPGRADE

Affected: < 5.19.7 · >= 6.0.0 and < 6.2.6

Fixed in: 5.19.7, 6.2.6

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 5.19.7 (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 web UPGRADE

Affected: < 5.19.7 · >= 6.0.0 and < 6.2.6

Fixed in: 5.19.7, 6.2.6

Safe to downgrade to: a release before 6.0.0

1. Check installed version

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

2. UPGRADE to 5.19.7 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade activemq-web

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

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

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

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-2026-42253?

activemq: upgrade to 5.19.7, 6.2.6; activemq web: upgrade to 5.19.7, 6.2.6. Exact commands for each OS are on this page.

Is CVE-2026-42253 being exploited?

CVE-2026-42253 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-2026-42253 affect?

CVE-2026-42253 affects activemq, activemq web. Severity is medium (CVSS 6.1). Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Apache ActiveMQ, Apache ActiveMQ Web. The MessageServlet in the ActiveMQ web console API copies every JMS message property into an HTTP r

How urgent is CVE-2026-42253?

Priority 43/100. On your watchlist

Software pages

Apache ActiveMQ vulnerabilities

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References

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