{"id":"CVE-2026-103399","title":"A flaw was found in SoupServer (libsoup)","summary":"A flaw was found in SoupServer (libsoup). When an HTTP/1.x client sends a request with Expect: 100-continue and a request body, and SoupServer returns an early final (non-1xx) response before the body is read, the server neither drains t…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","cwe":["CWE-444"],"vendor":"Red Hat","product":"libsoup3","affected":["libsoup3 (all versions)","libsoup","libsoup (all versions)","libsoup (all versions)","libsoup (all versions)"],"published":"2026-09-30","updated":"2026-09-30","sourceUpdated":"2026-09-30T20:17:30.987","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-103399","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-103399","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2543949","label":"secalert@redhat.com"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-30T19:10:59.353028Z"},"ingestedAt":"2026-09-30T18:17:24.540Z","slug":"CVE-2026-103399","body":"## Overview\n\nA flaw was found in SoupServer (libsoup). When an HTTP/1.x client sends a request with Expect: 100-continue and a request body, and SoupServer returns an early final (non-1xx) response before the body is read, the server neither drains the declared body bytes nor closes the connection. On a keep-alive connection, those leftover bytes are interpreted as a subsequent HTTP request. A remote, unauthenticated attacker can place a complete HTTP request in the body and cause SoupServer to process that smuggled request, leading to unintended request handling.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}