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CVE intelligence

CVE-2025-9901

Vulnerability intelligence

Published Sep 3, 2025Sources checked Sep 30, 2026
5.9MEDIUMCVSS out of 10
What this means

Review the available evidence

CVE-2025-9901 and is rated Medium severity with a CVSS score of 5.9. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

CISA KEVNot listedBased on the latest collected catalog
EPSS0.5%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview

What is CVE-2025-9901?

A flaw was found in libsoup’s caching mechanism, SoupCache, where the HTTP Vary header is ignored when evaluating cached responses. This header ensures that responses vary appropriately based on request headers such as language or authentication. Without this check, cached content can be incorrectly reused across different requests, potentially exposing sensitive user information. While the issue is unlikely to affect everyday desktop use, it could result in confidentiality breaches in proxy or multi-user environments.