CVE-2026-6918

No known exploitation. EPSS puts it in the 66th percentile. A vendor fix is available.

CVSS 3.17.5High EPSS percentile66th1.2% chance in 30 days CISA KEVNot listedNo confirmed exploitation
No public exploit known FixVendor fixNo build named by the sources

Published 2026-05-05Updated 2026-07-15Sources: CVE.org, NVD

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

Steps

Written by AI from the record

Check whether your Eclipse OpenJ9 deployment runs JITServer and whether its version is 0.21 through 0.58.
Upgrade Eclipse OpenJ9 to version 0.59 or later.
Until upgraded, restrict the JITServer TCP port so only approved internal JVM clients can reach it.
Review JITServer logs for unexpected crashes or repeated short network connections.

Vendor advisory Usually a quick update

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

In Eclipse Open9J versions 0.21 to 0.58, a pre-authentication remote attacker can crash JITServer by sending a 32-byte crafted TCP message.

In plain language

Written by AI from the record

Eclipse OpenJ9 JITServer versions 0.21 through 0.58 can be remotely crashed, so businesses using JITServer should upgrade to 0.59.

Pre-authentication remote denial of service in Eclipse OpenJ9 JITServer caused by crafted 32-byte TCP input triggering an out-of-bounds read/type-validation flaw.

If you're affected

JITServer service outage
Application performance disruption
Unplanned server restarts
Business application downtime

What is it

This flaw lets someone send a specially made network message that stops the JITServer service before they need to sign in. It is like someone being able to jam a business phone system with one malformed call: they do not get access to conversations, but they can prevent the service from working.

Who is affected

This matters to you if you run Eclipse OpenJ9 with its JITServer feature enabled. It is only a risk if JITServer accepts TCP connections that an attacker can reach.

How urgent is it

An attacker who can reach JITServer can send a crafted network message and make it crash. There is no record of active exploitation or publicly available exploit code, so this is an amber priority: upgrade promptly and limit network access while scheduling the change.

What to do — in detail

Confirm whether JITServer is installed, enabled, and listening for TCP connections, then identify the running Eclipse OpenJ9 version. Versions 0.21 through 0.58 are affected; upgrade to 0.59 or later, following your normal JVM runtime validation process because a runtime upgrade can require application compatibility testing. If patching must wait, isolate the JITServer listener with firewall rules or network segmentation so only known JVM clients can connect. No CISA KEV remediation due date applies because this CVE is not listed in KEV. Monitor JITServer and host logs for crashes, restarts, and unexpected connection attempts until the upgrade is complete.

Technical context

CVSS 3.1 score: 7.5 High (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). The issue is a pre-authentication remote denial of service against JITServer through a crafted 32-byte TCP message, associated with CWE-125 and CWE-1286. It is not listed in CISA KEV and no public exploit code is on record. EPSS is 0.5% (43rd percentile) with a flat trend; this is predictive rather than evidence of exploitation.

This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS66th

CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

1.2% chance of exploitation activity in the next 30 days, which ranks it in the 66th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

8 events over 135 days, from the signal feeds we watch.

2026-09-17OpenVAS check added
2026-07-15Patch availablerecord updated
2026-06-30Patch availablerecord updated
2026-05-05Publishedweakness classified, att&ck mapped

Affected products

Eclipse Foundationoss-project · DE
- Eclipse OpenJ9OSS Libraries
eclipseoss-project · BEaka eclipse-foundation
- openj9DevTools & CI

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

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

Scored 7.5 by NVD.

How it is reached

Attack Vector NetworkExploitable remotely over the network without any special conditions
Attack Complexity LowNo special conditions — the attack can be reliably reproduced
Privileges Required NoneNo authentication required — anyone can exploit this
User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

Confidentiality NoneNo confidentiality impact
Integrity NoneNo integrity impact
Availability HighTotal denial of service — the component is completely unavailable