CVE-2016-3144: Cross-site scripting (XSS) vulnerability in the Block Class module 7.x-2.x before 7.x-2.2 for Drupal allows re

Routine

MEDIUM 5.4DOWNGRADEMITIGATE

CVE-2016-3144 is a medium-severity flaw (CVSS 5.4) affecting block class, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cross-site scripting (XSS) vulnerability in the Block Class module 7.x-2.x before 7.x-2.2 for Drupal allows remote authenticated users with the "Administer block classes" permission to inject arbitrary web script or HTML via a class name.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	1.1% (top 34%)
CISA exploited list	No
Weakness	CWE-79
Published	2016-04-15
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: fedoraproject · fourkitchens

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2016-04-15 15:59 UTCPublished CVE record published
2026-06-17 00:45 UTCUpdated Record last modified

fourkitchens block class DOWNGRADE

Affected: 7.x-2.0 · 7.x-2.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.x-2.0

1. Check installed version

apt-cache policy block-class || rpm -q block-class || block-class --version

2. No fixed release: DOWNGRADE to a release before 7.x-2.0 (Debian / Ubuntu)

apt-cache madison block-class sudo apt install block-class=<VERSION_BEFORE_7.x-2.0> sudo apt-mark hold block-class

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list block-class sudo dnf downgrade block-class-<VERSION_BEFORE_7.x-2.0> sudo dnf versionlock add block-class

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.

fedoraproject fedora MITIGATE

Affected: 24

Fixed in: no fixed release known

Safe to downgrade to: a release before 24

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2016-3144?

block class: downgrade or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2016-3144 being exploited?

CVE-2016-3144 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-2016-3144 affect?

CVE-2016-3144 affects block class, fedora. Severity is medium (CVSS 5.4). Cross-site scripting (XSS) vulnerability in the Block Class module 7.x-2.x before 7.x-2.2 for Drupal allows remote authenticated users with the "Administer block classes" permission to inject arbitrary web script or HTML via a class name.

How urgent is CVE-2016-3144?

Priority 35/100. No elevated risk signals yet.

Software pages

Drupal vulnerabilities

Related CVEs

CVE-2025-3902 MEDIUM 6.1 UPGRADE Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Drupal B
CVE-2012-1657 LOW 2.1 DOWNGRADE Cross-site scripting (XSS) vulnerability in block_class.module in the Block Class module before 7.x-1.1 for Dr

References

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