ubuntu-cve-2026-45100
Vulnerability from osv_ubuntu
Published
2026-08-04 22:17
Modified
2026-08-04 22:17
Summary
Details
OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Versions 3.4.0-beta through 3.6.5 and 4.0.0-beta contain a buffer overflow in the {s.b64encode} string transformation. The size check for {s.b64encode} only verifies that the input fits within the 64 KB transformation buffer, but base64 encoding expands the data by roughly a third, so an input between about 49,153 and 65,535 bytes produces more output than the buffer can hold and overflows it by up to 21,844 bytes. Because these transformation buffers sit next to each other in memory and are reused for chained transformations, the overflow writes attacker-controlled data into the adjacent buffer and corrupts values used by later transformations processing the same SIP message. A remote attacker can trigger this by sending a SIP message with a large header value (roughly 50,000 bytes or more) when the routing script applies {s.b64encode} to attacker-controlled input, making exploitability dependent on the deployment's routing configuration. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.
Severity
9.1 (Critical)
N/A (UNKNOWN)
{
"affected": [
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "opensips",
"binary_version": "2.2.2-3build4"
},
{
"binary_name": "opensips-b2bua-module",
"binary_version": "2.2.2-3build4"
},
{
"binary_name": "opensips-berkeley-bin",
"binary_version": "2.2.2-3build4"
},
{
"binary_name": "opensips-berkeley-module",
"binary_version": "2.2.2-3build4"
},
{
"binary_name": "opensips-carrierroute-module",
"binary_version": "2.2.2-3build4"
},
{
"binary_name": "opensips-compression-module",
"binary_version": "2.2.2-3build4"
},
{
"binary_name": "opensips-console",
"binary_version": "2.2.2-3build4"
},
{
"binary_name": "opensips-cpl-module",
"binary_version": "2.2.2-3build4"
},
{
"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_name": "opensips-json-module",
"binary_version": "2.2.2-3build4"
},
{
"binary_name": "opensips-ldap-modules",
"binary_version": "2.2.2-3build4"
},
{
"binary_name": "opensips-lua-module",
"binary_version": "2.2.2-3build4"
},
{
"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_name": "opensips-postgres-module",
"binary_version": "2.2.2-3build4"
},
{
"binary_name": "opensips-presence-modules",
"binary_version": "2.2.2-3build4"
},
{
"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_name": "opensips-regex-module",
"binary_version": "2.2.2-3build4"
},
{
"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_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_version": "2.2.2-3build4"
},
{
"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"
}
]
},
"package": {
"ecosystem": "Ubuntu:18.04:LTS",
"name": "opensips",
"purl": "pkg:deb/ubuntu/opensips@2.2.2-3build4?arch=source\u0026distro=bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.2.2-3build2",
"2.2.2-3build3",
"2.2.2-3build4"
]
}
],
"aliases": [],
"details": "OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Versions 3.4.0-beta through 3.6.5 and 4.0.0-beta contain a buffer overflow in the {s.b64encode}\u00a0string transformation. The size check for {s.b64encode} only verifies that the input fits within the 64 KB transformation buffer, but base64 encoding expands the data by roughly a third, so an input between about 49,153 and 65,535 bytes produces more output than the buffer can hold and overflows it by up to 21,844 bytes. Because these transformation buffers sit next to each other in memory and are reused for chained transformations, the overflow writes attacker-controlled data into the adjacent buffer and corrupts values used by later transformations processing the same SIP message. A remote attacker can trigger this by sending a SIP message with a large header value (roughly 50,000 bytes or more) when the routing script applies \u00a0{s.b64encode}\u00a0 to attacker-controlled input, making exploitability dependent on the deployment\u0027s routing configuration. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.",
"id": "UBUNTU-CVE-2026-45100",
"modified": "2026-08-04T22:17:00Z",
"published": "2026-08-04T22:17:00Z",
"references": [
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-45100"
},
{
"type": "REPORT",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-45100"
},
{
"type": "REPORT",
"url": "https://github.com/OpenSIPS/opensips/commit/4d23613b65579b073784a07a65d3bf52443a4efb"
},
{
"type": "REPORT",
"url": "https://github.com/OpenSIPS/opensips/commit/5f103effaf5f372cccffe0b138f16998eba12668"
},
{
"type": "REPORT",
"url": "https://github.com/OpenSIPS/opensips/security/advisories/GHSA-35fr-6rv9-vp68"
}
],
"related": [],
"schema_version": "1.7.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"upstream": [
"CVE-2026-45100"
]
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
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