CVE-2026-81891Public exploitNetwork attack vectorHinoki check available

Remote code execution via ZIP MIME bypass

Published Aug 31, 2026 · Updated Sep 1, 2026

File upload bypass in Studio 42 Ltd. elFinder before 2.1.70 allows remote attackers to execute PHP code through ZIP extraction. checkExtractItems() sends extracted filenames from mimetypeInternalDetect() directly to allowPutMime() without mimeTypeNormalize(), so PHP extensions retain a permitted generic MIME type. Exploitation requires ZIP upload and extraction permission, a web-accessible files directory, uploadDeny blocking text/x-php, and a server configured to execute the extracted extension.

CVSS severity8.1
High
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

File upload bypass in Studio 42 Ltd. elFinder before 2.1.70 allows remote attackers to execute PHP code through ZIP extraction. checkExtractItems() sends extracted filenames from mimetypeInternalDetect() directly to allowPutMime() without mimeTypeNormalize(), so PHP extensions retain a permitted generic MIME type. Exploitation requires ZIP upload and extraction permission, a web-accessible files directory, uploadDeny blocking text/x-php, and a server configured to execute the extracted extension.

The record

CVE
CVE-2026-81891
Published
Aug 31, 2026
Updated
Sep 1, 2026
Vendor
Studio 42 Ltd.
Product
elFinder
Classifications
CWE-434, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 1, 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=< 2.1.70

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Studio 42 Ltd. · elFinderversion=< 2.1.70

Published CVSS scores

8.1GitHub CNACVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1190Exploit Public-Facing Application

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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