CVE-2025-4476

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.

CVSS v3.1

4.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

EPSS

0.39% chance of exploitation in the next 30 days, 32th percentile

Published

2025-05-16

Updated

2026-06-30

Proof-of-concept exploits (1)

• soltanali0/CVE-2025-4476-Exploit

References

• CVE Record
• NVD entry

Related

• CVE-2022-41082
• CVE-2023-7028
• CVE-2024-12877
• CVE-2024-38475
• CVE-2024-40725
• CVE-2024-4439