CVE-2026-89321Network attack vector

Disk exhaustion via unbounded VSIX entry extraction

Published Sep 14, 2026 · Updated Sep 14, 2026

Denial of service in Eclipse Open VSX 0.20.0 through 1.1.x allows remote authenticated users to exhaust temporary disk space via VSIX extraction. WebResourceService passes a ZipFile entry stream to Files.copy without counting decompressed bytes, then caches the complete output under the temporary directory with eviction limited by entry count rather than size. A namespace publisher must first upload a highly compressible VSIX, but extraction is triggered by an unauthenticated resource request; uncached resource and publishing requests then fail while the server remains running.

CVSS severityUnavailable
Unscored
EPSS probability0.27%
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 Open VSX 0.20.0 through 1.1.x allows remote authenticated users to exhaust temporary disk space via VSIX extraction. WebResourceService passes a ZipFile entry stream to Files.copy without counting decompressed bytes, then caches the complete output under the temporary directory with eviction limited by entry count rather than size. A namespace publisher must first upload a highly compressible VSIX, but extraction is triggered by an unauthenticated resource request; uncached resource and publishing requests then fail while the server remains running.

The record

CVE
CVE-2026-89321
Published
Sep 14, 2026
Updated
Sep 14, 2026
Vendor
The Eclipse Foundation
Product
Eclipse Open VSX
Classifications
T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 14, 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=0.20.0 <1.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Eclipse Foundation · Eclipse Open VSXversion=0.20.0 <1.2.0

Published CVSS scores

No CVSS assessment is available in this record.

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 exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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