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CVE Record

CVE-2026-6918: In Eclipse Open9J versions 0.21 to 0.58, a pre-authentication remote attacker can crash JITServer by sendin...

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.

HighCVSS 8.7Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-6918 is a high-severity denial-of-service issue in Eclipse OpenJ9 JITServer. A remote attacker does not need credentials and can crash JITServer with a crafted TCP message. The provided evidence points to availability impact only, not data theft or code execution.

Executive priority

Treat this as urgent where OpenJ9 JITServer is internet-facing or reachable by broad internal networks. The primary business risk is service outage, not confirmed compromise. Prioritize inventory, exposure reduction, and vendor-guided updates.

Technical view

The source bundle describes a pre-authentication network crash in Eclipse OpenJ9 JITServer affecting versions 0.21 through 0.58. CVSS 4.0 is 8.7 with network attack, low complexity, no privileges, no user interaction, and high vulnerable-system availability impact. Listed weaknesses are CWE-125 and CWE-1286.

Likely exposure

Exposure is most likely where Eclipse OpenJ9 JITServer is enabled and reachable over TCP, especially across untrusted networks. The bundle’s structured affected data is limited, so teams should confirm exact product/version applicability against Eclipse and Red Hat guidance.

Exploitation context

The bundle does not indicate CISA KEV listing or active exploitation. It does indicate pre-authentication remote denial of service with a small crafted TCP message, making exposed JITServer services higher priority for review.

Researcher notes

Evidence supports a network-triggered JITServer crash tied to out-of-bounds read and improper validation weakness classes. The bundle references an Eclipse advisory and pull request, but does not provide enough detail to name fixed versions or safe configuration changes beyond vendor guidance.

Mitigation direction

  • Check Eclipse OpenJ9 advisory GHSA-q393-vr4c-969r for official fixed versions.
  • Review Red Hat RHSA-2026:22328 if using Red Hat-packaged OpenJ9 components.
  • Limit JITServer TCP exposure to trusted networks only.
  • Inventory OpenJ9 JITServer deployments and prioritize reachable systems.
  • Monitor vendor advisories for corrected affected-version and package details.

Validation and detection

  • Identify systems running Eclipse OpenJ9 JITServer.
  • Confirm OpenJ9 versions against the 0.21 through 0.58 range stated in the bundle.
  • Check whether JITServer TCP listeners are reachable from untrusted networks.
  • Review package status against Red Hat CVE and VEX records where applicable.
  • Validate remediation by confirming vendor-advised fixed package or version levels.
Prepared
Confidence
medium
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-125: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cwe · low confidence lookup

CWE-1286: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-6918 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
8.7 (4.0)
Known Exploited
No
Published

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
7Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.7CVSS 4.0HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——eclipse
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat-SADP

Vulnerability scoring details

Base CVSS 4.0 score

8.7High
CVSS 4.0 vector shape for CVE-2026-6918Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPEclipse Open9J: Denial of Service in JITServer via crafted TCP message
other:Red Hat severity ratingcvssV3_1
  • 2026-05-05T13:01:31.087Z: Reported to Red Hat.
  • 2026-05-05T12:29:09.667Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Eclipse FoundationEclipse OpenJ90.21unaffected
Weakness

CWE details

CWE-125CWE-1286

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-125 · source CWE mapping

Out-of-bounds Read

Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-1286 · source CWE mapping

Improper Validation of Syntactic Correctness of Input

Improper Validation of Syntactic Correctness of Input represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs