CVE-2025-3519Network attack vector

Authenticated file replacement via reusable upload UUID

Published Apr 22, 2025 · Updated Apr 22, 2025

Authorization bypass in Unblu Spark 8.0.0 through 8.12.1 allows remote authenticated users to replace uploaded conversation files. The file-replacement path accepts an existing upload UUID without verifying that the requester uploaded the file or belongs to its conversation. Any conversation participant who obtains the random UUID can overwrite the file while its name, details, and uploader attribution remain unchanged; configured file interceptors and type restrictions still apply.

CVSS severity7.0
High
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Unblu Spark 8.0.0 through 8.12.1 allows remote authenticated users to replace uploaded conversation files. The file-replacement path accepts an existing upload UUID without verifying that the requester uploaded the file or belongs to its conversation. Any conversation participant who obtains the random UUID can overwrite the file while its name, details, and uploader attribution remain unchanged; configured file interceptors and type restrictions still apply.

The record

CVE
CVE-2025-3519
Published
Apr 22, 2025
Updated
Apr 22, 2025
Vendor
Unblu
Product
Unblu Spark
Classifications
CWE-639, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 22, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 2025Record 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=8.0.0 <=8.12.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Unblu · Unblu Sparkversion=8.0.0 <=8.12.1

Published CVSS scores

7.0Switzerland Government Common Vulnerability ProgramCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1565.001Stored Data Manipulation

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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