{"id":"CVE-2025-4476","title":"A denial-of-service vulnerability has been identified in the libsoup HTTP client library","summary":"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 wit…","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","cwe":["CWE-476"],"published":"2025-05-16","updated":"2026-06-25","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-4476","references":[{"url":"https://access.redhat.com/security/cve/CVE-2025-4476","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2366513","label":"secalert@redhat.com"},{"url":"https://gitlab.gnome.org/GNOME/libsoup/-/issues/440","label":"secalert@redhat.com"},{"url":"https://gitlab.gnome.org/GNOME/libsoup/-/work_items/440","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd","exploit-available"],"epss":0.00385,"epssPercentile":0.32404,"ingestedAt":"2026-06-29T13:24:34.207Z","exploits":{"github":1,"githubRepos":["https://github.com/soltanali0/CVE-2025-4476-Exploit"],"checkedAt":"2026-09-23T07:13:36.115Z"},"exploitAvailable":true,"slug":"CVE-2025-4476","body":"## Overview\n\nA 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":36,"depthScoreParts":{"impact":23.7,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":4824,"id":"CVE-2025-4476","ts":1788887209081,"field":"exploit_available","old":"false","new":"true"},{"seq":3707,"id":"CVE-2025-4476","ts":1788886326013,"field":"exploit_available","old":"true","new":"false"},{"seq":2552,"id":"CVE-2025-4476","ts":1788883007717,"field":"exploit_available","old":"false","new":"true"},{"seq":1581,"id":"CVE-2025-4476","ts":1788882407757,"field":"exploit_available","old":"true","new":"false"},{"seq":695,"id":"CVE-2025-4476","ts":1788881844939,"field":"exploit_available","old":"false","new":"true"}]}