Cyber Resilience

CVE-2026-16441

Eclipse Openj9 0.8.0 – 0.60.0

Published
21 July 2026
Modified
18 August 2026
Patch / advisory
View advisory
CVSS Score v4 6.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:N/VI:H/VA:L/SC:L/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0028 21th percentile
Risk Priority 35 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-16441 is a medium-severity Reliance on Undefined, Unspecified, or Implementation-Defined Behavior (CWE-758) vulnerability in Eclipse Openj9. Its CVSS base score is 6.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

In Eclipse OpenJ9 versions up to 0.60, when executing class files where a previously concrete superclass method has been recompiled as abstract, execution is incorrectly delegated to an interface default method.

CWE(s)
CWE-758

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
T1687 Exploitation for Defense Impairment Defense Impairment
Adversaries may exploit vulnerabilities in security software, infrastructure, or defensive components to degrade, disable, or otherwise continue to impair their ability to prevent, detect, or respond to malicious activity.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-3933Same product: Eclipse Openj9
CVE-2025-4447Same product: Eclipse Openj9
CVE-2026-16439Same product: Eclipse Openj9
CVE-2026-6918Same product: Eclipse Openj9
CVE-2023-2597Same product: Eclipse Openj9
CVE-2024-10917Same product: Eclipse Openj9
CVE-2023-5676Same product: Eclipse Openj9
CVE-2023-7272Same vendor: Eclipse
CVE-2024-10525Same vendor: Eclipse
CVE-2026-0648Same vendor: Eclipse

Affected Assets

eclipse
openj9
0.8.0 — 0.60.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover reliance on undefined behavior through cross-platform or stress testing.

SA-15 Development Process, Standards, and Tools partial match

Mandating a documented development process and coding standards directly discourages dependence on unspecified behavior.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can require use of only well-defined language and API behaviors during development.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-01 partial match
prevents

Consistent hardened configurations reduce the chance of relying on unspecified implementation details.

PR.PS-06 partial match
prevents

Secure SDLC practices directly prohibit use of undefined or implementation-defined behavior in code.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle requires defined, portable coding practices that reduce reliance on undefined behavior.

A.8.27 Secure system architecture and engineering principles partial match
degrades

Secure system architecture and engineering principles mandate use of well-specified interfaces and avoid undefined constructs.

A.8.28 Secure coding partial match
prevents

Secure coding explicitly prohibits constructs whose behavior is undefined, unspecified or implementation-defined.

A.8.29 Security testing in development and acceptance partial match
finds

Security testing can detect some instances of undefined behavior but does not prevent the root weakness.

References