{"id":"UBUNTU-CVE-2026-45103","details":"OpenSIPS is a Session Initiation Protocol (SIP) server implementation. In versions prior to 3.6.6 and 4.0.0-rc1, the TCP message framing layer parses the Content-Length header using unsigned int arithmetic with no overflow check. When an attacker sends a Content-Length value that overflows unsigned int (e.g., 4294967296), the framing layer computes a wrapped-around value (e.g., 0) and splits the TCP stream at the wrong boundary, causing the body of the first SIP message to be processed as a separate message and enabling SIP message smuggling. Because Content-Length is parsed in the transport layer before authentication, an unauthenticated, network-based attacker can smuggle arbitrary SIP messages over any TCP-based transport (proto_tcp, proto_tls, proto_ws, proto_wss) on any instance with TCP enabled, with no routing-script preconditions. This allows smuggled messages to bypass front-end SBC/proxy security policies, inherit the connection's authentication context, and evade rate limiting. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.","modified":"2026-08-06T03:09:02.055085379Z","published":"2026-08-04T22:17:00Z","upstream":["CVE-2026-45103"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-45103"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-45103"},{"type":"REPORT","url":"https://github.com/OpenSIPS/opensips/commit/4d23613b"},{"type":"REPORT","url":"https://github.com/OpenSIPS/opensips/commit/5f103eff"},{"type":"REPORT","url":"https://github.com/OpenSIPS/opensips/security/advisories/GHSA-jv35-555v-54jh"}],"affected":[{"package":{"name":"opensips","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/opensips?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.2-3build2","2.2.2-3build3","2.2.2-3build4"],"ecosystem_specific":{"binaries":[{"binary_version":"2.2.2-3build4","binary_name":"opensips"},{"binary_name":"opensips-b2bua-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-berkeley-bin","binary_version":"2.2.2-3build4"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-berkeley-module"},{"binary_name":"opensips-carrierroute-module","binary_version":"2.2.2-3build4"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-compression-module"},{"binary_name":"opensips-console","binary_version":"2.2.2-3build4"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-cpl-module"},{"binary_name":"opensips-dbhttp-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-dialplan-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-emergency-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-geoip-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-http-modules","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-identity-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-jabber-module","binary_version":"2.2.2-3build4"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-json-module"},{"binary_name":"opensips-ldap-modules","binary_version":"2.2.2-3build4"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-lua-module"},{"binary_name":"opensips-memcached-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-mysql-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-perl-modules","binary_version":"2.2.2-3build4"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-postgres-module"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-presence-modules"},{"binary_name":"opensips-rabbitmq-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-radius-modules","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-redis-module","binary_version":"2.2.2-3build4"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-regex-module"},{"binary_name":"opensips-restclient-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-sctp-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-snmpstats-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-sqlite-module","binary_version":"2.2.2-3build4"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-tls-module"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-tlsmgm-module"},{"binary_version":"2.2.2-3build4","binary_name":"opensips-unixodbc-module"},{"binary_name":"opensips-wss-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-xmlrpc-module","binary_version":"2.2.2-3build4"},{"binary_name":"opensips-xmpp-module","binary_version":"2.2.2-3build4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-45103.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},{"type":"Ubuntu","score":"medium"}]}