{"cve":{"cve_id":"CVE-2026-66338","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.0019,"epss_percentile":0.08681,"epss_as_of":"2026-08-26","description":"A flaw was found in libsoup. The chunked transfer encoding parser uses a permissive parsing function for chunk sizes that silently accepts inputs violating RFC 9112, including leading whitespace, plus sign prefixes, and trailing invalid characters. When libsoup operates behind a strict frontend proxy, this parsing differential can be exploited to smuggle HTTP requests.","published_at":"2026-07-24T23:01:20.503000Z","last_modified_at":"2026-08-24T16:44:22.590000Z","cvss_v3_score":5.4,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"none","ssvc_automatable":false,"ssvc_technical_impact":"partial","cwes":["CWE-444"],"nvd_references":["https://access.redhat.com/security/cve/CVE-2026-66338","https://bugzilla.redhat.com/show_bug.cgi?id=2506950"],"vuln_status":"Analyzed","trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-07-25T00:48:49.722866Z","updated_at":"2026-08-24T19:35:50.286612Z"},"effective_severity":"MEDIUM","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"H","value_label":"High"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"C","value_label":"Changed"},{"metric":"C","name":"Confidentiality","value":"L","value_label":"Low"},{"metric":"I","name":"Integrity","value":"L","value_label":"Low"},{"metric":"A","name":"Availability","value":"N","value_label":"None"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"gnome","vendor_name":"GNOME","product_slug":"libsoup","product_name":"libsoup","version_start":null,"version_start_inclusive":null,"version_end":null,"version_end_inclusive":null,"cpe23_uri":"cpe:2.3:a:gnome:libsoup:-:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"enterprise-linux","product_name":"enterprise_linux","version_start":"6.0","version_start_inclusive":true,"version_end":"6.0","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"enterprise-linux","product_name":"enterprise_linux","version_start":"7.0","version_start_inclusive":true,"version_end":"7.0","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"enterprise-linux","product_name":"enterprise_linux","version_start":"8.0","version_start_inclusive":true,"version_end":"8.0","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"enterprise-linux","product_name":"enterprise_linux","version_start":"9.0","version_start_inclusive":true,"version_end":"9.0","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*"},{"vendor_slug":"redhat","vendor_name":"RedHat","product_slug":"enterprise-linux","product_name":"enterprise_linux","version_start":"10.0","version_start_inclusive":true,"version_end":"10.0","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*"}],"exploit_refs":[],"news":[],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-66338","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2506950","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2026-07-24T23:01:20.503000Z","label":"CVE published","source":null},{"type":"ssvc_changed","at":"2026-07-27T19:04:23.263756Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-07-27T19:04:23.263756Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-07-27T19:04:23.263756Z","label":"SSVC decision revised","source":"vulnrichment"}]}