CVE-2026-45103
📛 CVE Title
OpenSIPS: SIP Message Smuggling via TCP Content-Length Integer Overflow
Description
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.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- GitHub_M
- CVSS severity
- HIGH
- CVSS score
- 7.5 / 10
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- Effective score
- 7.5 / 10 HIGH source: CNA overview
- CWE(s)
-
CWE-190 - Reserved
- 2026-05-08
- Published
- 2026-08-04 21:56 UTC
- Last updated
- 2026-08-04 21:56 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/45xxx/CVE-2026-45103.json
- Linked Threat
- CVE-2026-45103 — OpenSIPS: SIP Message Smuggling via TCP Content-Length Integer Overflow
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| OpenSIPS | opensips |
>= 3.4.0, < 3.6.6 (affected),
>= 4.0.0-beta, < 4.0.0-rc1 (affected)
|
— |
Vendor references (3)
References embedded in the original CVE record by the assigning CNA.
- https://github.com/OpenSIPS/opensips/security/advisories/GHSA-jv35-555v-54jh x_refsource_CONFIRM
- https://github.com/OpenSIPS/opensips/commit/4d23613b x_refsource_MISC
- https://github.com/OpenSIPS/opensips/commit/5f103eff x_refsource_MISC
Web references (0)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
No web references attached yet.
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-45103.json.
{
"containers": {
"cna": {
"affected": [
{
"product": "opensips",
"vendor": "OpenSIPS",
"versions": [
{
"status": "affected",
"version": ">= 3.4.0, < 3.6.6"
},
{
"status": "affected",
"version": ">= 4.0.0-beta, < 4.0.0-rc1"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-190",
"description": "CWE-190: Integer Overflow or Wraparound",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-04T21:56:57.422Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/OpenSIPS/opensips/security/advisories/GHSA-jv35-555v-54jh",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/OpenSIPS/opensips/security/advisories/GHSA-jv35-555v-54jh"
},
{
"name": "https://github.com/OpenSIPS/opensips/commit/4d23613b",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/OpenSIPS/opensips/commit/4d23613b"
},
{
"name": "https://github.com/OpenSIPS/opensips/commit/5f103eff",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/OpenSIPS/opensips/commit/5f103eff"
}
],
"source": {
"advisory": "GHSA-jv35-555v-54jh",
"discovery": "UNKNOWN"
},
"title": "OpenSIPS: SIP Message Smuggling via TCP Content-Length Integer Overflow"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-45103",
"datePublished": "2026-08-04T21:56:57.422Z",
"dateReserved": "2026-05-08T19:27:26.699Z",
"dateUpdated": "2026-08-04T21:56:57.422Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}