Description

A denial-of-service vulnerability has been identified in the libsoup HTTP client library. This flaw can be triggered when a libsoup client receives a 401 (Unauthorized) HTTP response containing a specifically crafted domain parameter within the WWW-Authenticate header. Processing this malformed header can lead to a crash of the client application using libsoup. An attacker could exploit this by setting up a malicious HTTP server. If a user's application using the vulnerable libsoup library connects to this malicious server, it could result in a denial-of-service. Successful exploitation requires tricking a user's client application into connecting to the attacker's malicious server.

Classification

CVE ID: CVE-2025-4476

CVSS Base Severity: MEDIUM

CVSS Base Score: 4.3

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

Affected Products

Vendor: Red Hat

Product: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 7.23% (scored less or equal to compared to others)

EPSS Date: 2025-06-14 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-4476
https://access.redhat.com/security/cve/CVE-2025-4476
https://bugzilla.redhat.com/show_bug.cgi?id=2366513

Timeline