CVE-2018-18940: servlet/SnoopServlet (a servlet installed by default) in Netscape Enterprise 3.63 has reflected XSS via an arb

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MEDIUM 6.1DOWNGRADE

CVE-2018-18940 is a medium-severity flaw (CVSS 6.1) affecting enterprise server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

servlet/SnoopServlet (a servlet installed by default) in Netscape Enterprise 3.63 has reflected XSS via an arbitrary parameter=[XSS] in the query string. A remote unauthenticated attacker could potentially exploit this vulnerability to supply malicious HTML or JavaScript code to a vulnerable web application, which is then reflected back to the victim and executed by the web browser. NOTE: this product is discontinued.

Why this priority

Public exploit reference

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

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.4% (top 27%)
CISA exploited list	No
Weakness	CWE-79
Published	2019-01-31
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: netscape

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

Am I affected?

Timeline

2019-01-31 19:29 UTCPublished CVE record published
2026-06-17 01:48 UTCUpdated Record last modified

netscape enterprise server DOWNGRADE

Affected: 3.63

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.63

1. Check installed version

apt-cache policy enterprise-server || rpm -q enterprise-server || enterprise-server --version

2. No fixed release: DOWNGRADE to a release before 3.63 (Debian / Ubuntu)

apt-cache madison enterprise-server sudo apt install enterprise-server=<VERSION_BEFORE_3.63> sudo apt-mark hold enterprise-server

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

dnf --showduplicates list enterprise-server sudo dnf downgrade enterprise-server-<VERSION_BEFORE_3.63> sudo dnf versionlock add enterprise-server

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-2018-18940?

enterprise server: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-18940 being exploited?

CVE-2018-18940 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-2018-18940 affect?

CVE-2018-18940 affects enterprise server. Severity is medium (CVSS 6.1). servlet/SnoopServlet (a servlet installed by default) in Netscape Enterprise 3.63 has reflected XSS via an arbitrary parameter=[XSS] in the query string. A remote unauthenticated attacker could potentially exploit this vulnerability to supp

How urgent is CVE-2018-18940?

Priority 45/100. Public exploit reference

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References

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