CVE-2018-16887: A cross-site scripting (XSS) flaw was found in the katello component of Satellite

Q: How do I fix CVE-2018-16887?

satellite: downgrade or apply the listed mitigation; katello: upgrade to 3.9.0. Exact commands for each OS are on this page.

Q: Is CVE-2018-16887 being exploited?

CVE-2018-16887 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2018-16887 affect?

CVE-2018-16887 affects satellite, katello. Severity is medium (CVSS 5.4). A cross-site scripting (XSS) flaw was found in the katello component of Satellite. An attacker with privilege to create/edit organizations and locations is able to execute a XSS attacks against other users through the Subscriptions or the R

Q: How urgent is CVE-2018-16887?

Priority 45/100. Public exploit reference; On your watchlist

This month

MEDIUM 5.4WATCHLISTDOWNGRADEUPGRADE

CVE-2018-16887 is a medium-severity flaw (CVSS 5.4) affecting satellite, katello. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A cross-site scripting (XSS) flaw was found in the katello component of Satellite. An attacker with privilege to create/edit organizations and locations is able to execute a XSS attacks against other users through the Subscriptions or the Red Hat Repositories wizards. This can possibly lead to malicious code execution and extraction of the anti-CSRF token of higher privileged users. Versions before 3.9.0 are vulnerable.

Why this priority

Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	1.0% (top 37%)
CISA exploited list	No
Weakness	CWE-79
Published	2019-01-13
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: redhat · theforeman

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

Am I affected?

Timeline

2019-01-13 02:29 UTCPublished CVE record published
2026-06-17 01:44 UTCUpdated Record last modified

redhat satellite DOWNGRADE

Affected: 6.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 6.0 (Debian / Ubuntu)

apt-cache madison satellite sudo apt install satellite=<VERSION_BEFORE_6.0> sudo apt-mark hold satellite

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

dnf --showduplicates list satellite sudo dnf downgrade satellite-<VERSION_BEFORE_6.0> sudo dnf versionlock add satellite

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.

theforeman katello UPGRADE

Affected: < 3.9.0

Fixed in: 3.9.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 3.9.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade katello

Note

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

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-2018-16887?

satellite: downgrade or apply the listed mitigation; katello: upgrade to 3.9.0. Exact commands for each OS are on this page.

Is CVE-2018-16887 being exploited?

CVE-2018-16887 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-2018-16887 affect?

CVE-2018-16887 affects satellite, katello. Severity is medium (CVSS 5.4). A cross-site scripting (XSS) flaw was found in the katello component of Satellite. An attacker with privilege to create/edit organizations and locations is able to execute a XSS attacks against other users through the Subscriptions or the R

How urgent is CVE-2018-16887?

Priority 45/100. Public exploit reference; On your watchlist

Related CVEs

CVE-2012-0059 MEDIUM 4.9 DOWNGRADE DOWNGRADE A flaw was found in Spacewalk-backend
CVE-2011-4346 MEDIUM 4.6 DOWNGRADE Cross-site scripting (XSS) vulnerability in the web interface in Red Hat Network (RHN) Satellite allows remote
CVE-2013-2056 HIGH 7.5 DOWNGRADE A flaw was found in Red Hat Network Satellite
CVE-2012-5562 HIGH 8.6 UPGRADE A flaw was found in rhn-proxy
CVE-2026-12112 HIGH 7.8 DOWNGRADE MITIGATE A flaw was found in the foreman-mcp-server

References

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