CVE-2026-34745Public exploitNetwork attack vector

Unauthenticated file write via unsanitized upload checksum

Published Apr 2, 2026 · Updated Apr 2, 2026

Path traversal in Shane Israel Fireshare before 1.5.3 allows remote attackers to write arbitrary files through the public chunked-upload API. The public_upload_videoChunked function passes the unsanitized checkSum form value to os.path.join and opens the resulting path for appending attacker-controlled upload data. Exploitation requires allow_public_upload to be enabled; writes are limited to server paths writable by the Fireshare process and to supported file extensions.

CVSS severity9.1
Critical
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Shane Israel Fireshare before 1.5.3 allows remote attackers to write arbitrary files through the public chunked-upload API. The public_upload_videoChunked function passes the unsanitized checkSum form value to os.path.join and opens the resulting path for appending attacker-controlled upload data. Exploitation requires allow_public_upload to be enabled; writes are limited to server paths writable by the Fireshare process and to supported file extensions.

The record

CVE
CVE-2026-34745
Published
Apr 2, 2026
Updated
Apr 2, 2026
Vendor
Shane Israel
Product
Fireshare
Classifications
CWE-22, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 2, 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=< 1.5.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Shane Israel · Fireshareversion=< 1.5.3

Published CVSS scores

9.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
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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