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CVE-2025-3519

HIGHCVSS 7/10EPSS 0.24%

Last modified

CVE-2025-3519 is a high-severity vulnerability rated 7/10 on the CVSS scale. An authorization bypass in Unblu Spark allows a participant of a conversation to replace an existing, uploaded file. Every uploaded file in Unblu gets assigned with a randomly generated Universally Unique ID (UUID). In case a participant of this or another conversation gets access to such a file ID, it can be used to replace the file without changing the file name and details or the name of the user who uploaded the file. EPSS estimates a 0.24% chance of exploitation in the next 30 days.

Description

An authorization bypass in Unblu Spark allows a participant of a conversation to replace an existing, uploaded file. Every uploaded file in Unblu gets assigned with a randomly generated Universally Unique ID (UUID). In case a participant of this or another conversation gets access to such a file ID, it can be used to replace the file without changing the file name and details or the name of the user who uploaded the file. During the upload, file interception and allowed file type rules are still applied correctly.

Metrics

CVSS 4.0
7/10

CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability
0.24%

14.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2025-3519?
An authorization bypass in Unblu Spark allows a participant of a conversation to replace an existing, uploaded file. Every uploaded file in Unblu gets assigned with a randomly generated Universally Unique ID (UUID). In case a participant of this or another conversation gets access to such a file ID, it can be used to replace the file without changing the file name and details or the name of the user who uploaded the file. During the upload, file interception and allowed file type rules are still applied correctly.
How severe is CVE-2025-3519?
CVE-2025-3519 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 0.24% probability of exploitation in the next 30 days.
How do I fix CVE-2025-3519?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST