CVE-2020-11050: In Java-WebSocket less than or equal to 1.4.1, there is an Improper Validation of Certificate with Host Mismat

Q: How do I fix CVE-2020-11050?

java-websocket: upgrade to newer than 1.4.1. Exact commands for each OS are on this page.

Q: Is CVE-2020-11050 being exploited?

CVE-2020-11050 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-2020-11050 affect?

CVE-2020-11050 affects java-websocket. Severity is critical (CVSS 9.0). In Java-WebSocket less than or equal to 1.4.1, there is an Improper Validation of Certificate with Host Mismatch where WebSocketClient does not perform SSL hostname validation. This has been patched in 1.5.0.

Q: How urgent is CVE-2020-11050?

Priority 51/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.0REMOTEUPGRADE

CVE-2020-11050 is a critical-severity flaw (CVSS 9.0) affecting java-websocket. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Java-WebSocket less than or equal to 1.4.1, there is an Improper Validation of Certificate with Host Mismatch where WebSocketClient does not perform SSL hostname validation. This has been patched in 1.5.0.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.0 (Critical)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-297, CWE-295
Published	2020-05-07
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: java-websocket project

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

Am I affected?

Timeline

2020-05-07 21:15 UTCPublished CVE record published
2026-06-17 02:48 UTCUpdated Record last modified

java-websocket project java-websocket UPGRADE

Affected: <= 1.4.1

Fixed in: newer than 1.4.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy java-websocket || rpm -q java-websocket || java-websocket --version

2. UPGRADE to newer than 1.4.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade java-websocket

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade java-websocket

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-2020-11050?

java-websocket: upgrade to newer than 1.4.1. Exact commands for each OS are on this page.

Is CVE-2020-11050 being exploited?

CVE-2020-11050 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-2020-11050 affect?

CVE-2020-11050 affects java-websocket. Severity is critical (CVSS 9.0). In Java-WebSocket less than or equal to 1.4.1, there is an Improper Validation of Certificate with Host Mismatch where WebSocketClient does not perform SSL hostname validation. This has been patched in 1.5.0.

How urgent is CVE-2020-11050?

Priority 51/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

Java vulnerabilities

References

← Back to latest CVEs