CVE-2025-4476

MEDIUM 1 PoC

MEDIUM Priority: 0.02 BB Relevance: 69/100

Published: 2025-05-16 Modified: 2026-11-06 First seen: 2026-11-06 Status: active

Attack Surface

Network Low Complexity No Auth

CVSS Vector Breakdown

AV: Network

AC: Low

PR: None

UI: Required

S: Unchanged

C: None

I: None

A: Low

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.