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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
CVSS 7.5 / 10 7.5 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)

VendorProductVersionsPlatforms
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.

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"
}