CVE-2017-1000209: The Java WebSocket client nv-websocket-client does not verify that the server hostname matches a domain name i

Q: How do I fix CVE-2017-1000209?

nv-websocket-client: upgrade to newer than 2.2. Exact commands for each OS are on this page.

Q: Is CVE-2017-1000209 being exploited?

CVE-2017-1000209 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-2017-1000209 affect?

CVE-2017-1000209 affects nv-websocket-client. Severity is medium (CVSS 5.9). The Java WebSocket client nv-websocket-client does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spo

Q: How urgent is CVE-2017-1000209?

Priority 39/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.9REMOTEUPGRADE

CVE-2017-1000209 is a medium-severity flaw (CVSS 5.9) affecting nv-websocket-client. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Java WebSocket client nv-websocket-client does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL/TLS servers via an arbitrary valid certificate.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 48%)
CISA exploited list	No
Weakness	CWE-295
Published	2017-11-17
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: nv-websocket-client project

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

Am I affected?

Timeline

2017-11-17 02:29 UTCPublished CVE record published
2026-06-17 00:58 UTCUpdated Record last modified

nv-websocket-client project nv-websocket-client UPGRADE

Affected: <= 2.2

Fixed in: newer than 2.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy nv-websocket-client || rpm -q nv-websocket-client || nv-websocket-client --version

2. UPGRADE to newer than 2.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade nv-websocket-client

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade nv-websocket-client

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-2017-1000209?

nv-websocket-client: upgrade to newer than 2.2. Exact commands for each OS are on this page.

Is CVE-2017-1000209 being exploited?

CVE-2017-1000209 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-2017-1000209 affect?

CVE-2017-1000209 affects nv-websocket-client. Severity is medium (CVSS 5.9). The Java WebSocket client nv-websocket-client does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spo

How urgent is CVE-2017-1000209?

Priority 39/100. Remotely exploitable, no login, no user action

Software pages

Java vulnerabilities

References

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