UBUNTU-CVE-2026-50161 (CVE-2026-50161)

Vulnerability from osv_ubuntu – Published: 2026-08-18 18:17 – Updated: 2026-09-23 23:30 – Source website
VLAI
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->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.

Severity
9.3 (Critical)
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
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "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": "2.0.1-3build1"
          }
        ]
      },
      "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": "2026-09-23T23:30:20Z",
  "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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