CVE-2025-4476: libsoup2.4 NULL Pointer Dereference

Vulnerability summary

CVE-2025-4476 is a medium (CVSS 4.3) NULL Pointer Dereference vulnerability in libsoup2.4. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 32.5% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 16-05-2025
   PublishedVulnerability first disclosed.
2. 30-06-2026
   Last modifiedVulnerability information updated.

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.

• CWE-476NULL Pointer DereferenceThe product dereferences a pointer that it expects to be valid but is NULL.