How severe is CVE-2019-20366?

CVE-2019-20366 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2019-20366?

CVE-2019-20366 affects the following packages: org.igniterealtime.openfire:parent (Maven). Ecosystems affected: Maven.

How do I fix CVE-2019-20366?

Update org.igniterealtime.openfire:parent to 4.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-20366 is resolved across your whole dependency graph.

How do I detect CVE-2019-20366 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.igniterealtime.openfire:parent, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2019-20366 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2019-20366 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2019-20366, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2019-20366?

CVE-2019-20366 has an EPSS (Exploit Prediction Scoring System) score of 1.3%, placing it in the 70th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2019-20366?

CVE-2019-20366 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2019-20366 published, and has it been updated?

CVE-2019-20366 was published on January 8, 2020 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2019-20366 — parent

MEDIUMFix: igniterealtime/Openfire#1561

CVE-2019-20366 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in org.igniterealtime.openfire:parent. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for org.igniterealtime.openfire:parent — see the affected versions and patch details below.

XSS in Ignite Realtime Openfire via isTrustStore

Also known asGHSA-m6pr-xcrm-4qqp

Published

Jan 8, 2020

Updated

Oct 20, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs70th percentile — riskier than 70% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

☕org.igniterealtime.openfire:parent

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

An XSS issue was discovered in Ignite Realtime Openfire 4.4.4 via isTrustStore to Manage Store Contents.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.igniterealtime.openfire:parent`	all versions	4.5.0`org.igniterealtime.openfire:parent:4.5.0`

Affected Products

1 product · 1 configurations

Application

openfireigniterealtime

1 version

4.4.4

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

An XSS issue was discovered in Ignite Realtime Openfire 4.4.4 via isTrus…

cybersecurityworks.comNVDNov 2020

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.igniterealtime.openfire:parent, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.igniterealtime.openfire:parent to 4.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-20366 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

An XSS issue was discovered in Ignite Realtime Openfire 4.4.4 via isTrustStore to Manage Store Contents.

O3 Security · Impact-Aware SCA

Is CVE-2019-20366 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CWE Classification

CWE-79Cross-site Scripting (XSS)

Weaponization

No Nuclei template or Metasploit module yet. 1 public proof-of-concept reference is listed on this page.

OpenSSF Scorecard

Package health score

Openfire

3.6/10

Code-Review9/10

Maintained10/10

Branch-Protection0/10

Assessed Oct 19, 2026

Timeline

Disclosed

Jan 8, 2020

First exploit

Nov 10, 2020

Last updated

Oct 20, 2026

Identifiers

CVE-2019-20366

GHSA-m6pr-xcrm-4qqp

References

Advisorygithub.com Advisorynvd.nist.gov · CVE 2019 20366 Reportissues.igniterealtime.org · OF 1955 Webgithub.com · fef55d4be50da8f66f468d9e7d822528acb8273d Packagegithub.com · Openfire Evidencecybersecurityworks.com · cve 2019 20366 openfire

Related vulnerabilities

This CVE is medium severity; 8 of 8 other CVEs affecting parent are rated as high or higher (top: critical).

CVE-2019-20527CVE-2019-18393CVE-2019-20526CVE-2019-20525CVE-2019-18394CVE-2014-2741CVE-2017-15911CVE-2018-11688

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 20, 2026