CVE-2026-16440Public exploitNetwork attack vector

JVM crash via recursive annotation parsing

Published Aug 19, 2026 · Updated Aug 19, 2026

Denial of service in Eclipse OpenJ9 0.60 and earlier allows attackers to crash the JVM via a crafted .class file with nested annotations. The class file reader in runtime/bcutil/cfreader.c recurses between readAnnotations() and readAnnotationElement() without a nesting limit, exhausting native stack space and triggering SIGSEGV during class loading. Reachability depends on a target accepting and loading attacker-supplied class files; the published impact is process termination rather than code execution or data exposure.

CVSS severity5.7
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Eclipse OpenJ9 0.60 and earlier allows attackers to crash the JVM via a crafted .class file with nested annotations. The class file reader in runtime/bcutil/cfreader.c recurses between readAnnotations() and readAnnotationElement() without a nesting limit, exhausting native stack space and triggering SIGSEGV during class loading. Reachability depends on a target accepting and loading attacker-supplied class files; the published impact is process termination rather than code execution or data exposure.

The record

CVE
CVE-2026-16440
Published
Aug 19, 2026
Updated
Aug 19, 2026
Vendor
The Eclipse Foundation
Product
Eclipse OpenJ9
Classifications
CWE-674, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.8.0 <0.60

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Eclipse Foundation · Eclipse OpenJ9version=0.8.0 <0.60

Published CVSS scores

5.7Eclipse FoundationCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-674Uncontrolled Recursion
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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