UBUNTU-CVE-2026-50161 (CVE-2026-50161)
Vulnerability from osv_ubuntu – Published: 2026-08-18 18:17 – Updated: 2026-10-17 09:44 – Source websitelibre is a generic library for real-time communications with asynchronous input and output support. Prior to 4.8.1, the websock_decode() function in src/websock/websock.c contains an integer overflow when validating a masked WebSocket frame that uses the 64-bit extended length encoding. The expression 4 + hdr->len can wrap when hdr->len is close to UINT64_MAX, causing the mbuf_get_left() bounds check to pass. The subsequent XOR unmasking loop then writes beyond the heap buffer. Applications using websock_accept() or websock_accept_proto() to implement a WebSocket server are affected, and exploitation can cause attacker-controlled heap corruption or denial of service after the HTTP WebSocket upgrade handshake. This issue is fixed in version 4.8.1.
{
"affected": [
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libre0",
"binary_version": "0.4.14-4"
}
]
},
"package": {
"ecosystem": "Ubuntu:16.04:LTS",
"name": "libre",
"purl": "pkg:deb/ubuntu/libre@0.4.14-4?arch=source\u0026distro=xenial"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"0.4.14-1",
"0.4.14-2",
"0.4.14-3",
"0.4.14-4"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libre0",
"binary_version": "0.5.6-1ubuntu2"
}
]
},
"package": {
"ecosystem": "Ubuntu:18.04:LTS",
"name": "libre",
"purl": "pkg:deb/ubuntu/libre@0.5.6-1ubuntu2?arch=source\u0026distro=bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"0.5.4-3ubuntu1",
"0.5.5-1ubuntu1",
"0.5.6-1ubuntu1",
"0.5.6-1ubuntu2"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libre0",
"binary_version": "0.6.0-4"
}
]
},
"package": {
"ecosystem": "Ubuntu:20.04:LTS",
"name": "libre",
"purl": "pkg:deb/ubuntu/libre@0.6.0-4?arch=source\u0026distro=focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"0.6.0-4"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libre0",
"binary_version": "1.1.0-1build1"
}
]
},
"package": {
"ecosystem": "Ubuntu:22.04:LTS",
"name": "libre",
"purl": "pkg:deb/ubuntu/libre@1.1.0-1build1?arch=source\u0026distro=jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.1.0-1",
"1.1.0-1build1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libre0",
"binary_version": "1.1.0-1build4"
}
]
},
"package": {
"ecosystem": "Ubuntu:24.04:LTS",
"name": "libre",
"purl": "pkg:deb/ubuntu/libre@1.1.0-1build4?arch=source\u0026distro=noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.1.0-1build2",
"1.1.0-1build3",
"1.1.0-1build4"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libre1",
"binary_version": "2.0.1-3ubuntu1"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.10",
"name": "libre",
"purl": "pkg:deb/ubuntu/libre@2.0.1-3ubuntu1?arch=source\u0026distro=stonking"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.0.1-3build1",
"2.0.1-3ubuntu1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libre1",
"binary_version": "2.0.1-3build1"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.04:LTS",
"name": "libre",
"purl": "pkg:deb/ubuntu/libre@2.0.1-3build1?arch=source\u0026distro=resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.0.1-3",
"2.0.1-3build1"
]
}
],
"aliases": [],
"details": "libre is a generic library for real-time communications with asynchronous input and output support. Prior to 4.8.1, the websock_decode() function in src/websock/websock.c contains an integer overflow when validating a masked WebSocket frame that uses the 64-bit extended length encoding. The expression 4 + hdr-\u003elen can wrap when hdr-\u003elen is close to UINT64_MAX, causing the mbuf_get_left() bounds check to pass. The subsequent XOR unmasking loop then writes beyond the heap buffer. Applications using websock_accept() or websock_accept_proto() to implement a WebSocket server are affected, and exploitation can cause attacker-controlled heap corruption or denial of service after the HTTP WebSocket upgrade handshake. This issue is fixed in version 4.8.1.",
"id": "UBUNTU-CVE-2026-50161",
"modified": "2026-10-17T09:44:21Z",
"published": "2026-08-18T18:17:00Z",
"references": [
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-50161"
},
{
"type": "REPORT",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-50161"
},
{
"type": "REPORT",
"url": "https://github.com/baresip/re/security/advisories/GHSA-hvxv-v2gp-v93h"
},
{
"type": "REPORT",
"url": "https://github.com/baresip/re/pull/1584"
}
],
"related": [],
"schema_version": "1.7.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"upstream": [
"CVE-2026-50161"
]
}
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