open62541 — security advisory

{
  "id": "f2ad5bbbca920badc852d133dac037d773a8112fdae1d40ab9c1b2e552838d1f",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-11946",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-11946",
    "summary": "An unauthenticated remote attacker can exhaust server memory via the GetEndpoints Discovery Service in open62541. The endpointUrl field of GetEndpointsRequest is not validated for length. An attacker can declare an arbitrarily large string (up to ~4.09 GB via the UInt32 length field) delivered across intermediate chunks without ever sending the final chunk. The server buffers all chunks in RAM indefinitely until the SecureChannel times out. The attack is pre-session and bypasses all encryption configurations. The issue affects open62541: from 1.4.0 through 1.4.16, from 1.5.0 through 1.5.4, master.",
    "evidence": "osv:UBUNTU-CVE-2026-11946",
    "products": [
      {
        "name": {
          "value": "open62541",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.4.6-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.4.11.1-1",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "open62541",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.4.11.1-1build1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.4.18-1",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "open62541",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.4.11.1-1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "1.4.11.1-1build1",
            "evidence": "/affected/2/versions"
          }
        ]
      }
    ],
    "severity": "high",
    "structured": {
      "id": "UBUNTU-CVE-2026-11946",
      "aliases": [
        "UBUNTU-CVE-2026-11946"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "open62541",
            "purl": "pkg:deb/ubuntu/open62541?arch=source&distro=questing",
            "ecosystem": "Ubuntu:25.10"
          },
          "versions": [
            "1.4.6-1",
            "1.4.11.1-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-11946.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libopen62541-1.4",
                "binary_version": "1.4.11.1-1"
              },
              {
                "binary_name": "libopen62541-1.4-tools",
                "binary_version": "1.4.11.1-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "open62541",
            "purl": "pkg:deb/ubuntu/open62541?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "1.4.11.1-1build1",
            "1.4.18-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-11946.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libopen62541-1.4",
                "binary_version": "1.4.18-1"
              },
              {
                "binary_name": "libopen62541-1.4-tools",
                "binary_version": "1.4.18-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "open62541",
            "purl": "pkg:deb/ubuntu/open62541?arch=source&distro=resolute",
            "ecosystem": "Ubuntu:26.04:LTS"
          },
          "versions": [
            "1.4.11.1-1",
            "1.4.11.1-1build1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-11946.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libopen62541-1.4",
                "binary_version": "1.4.11.1-1build1"
              },
              {
                "binary_name": "libopen62541-1.4-tools",
                "binary_version": "1.4.11.1-1build1"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T12:58:04.706364328Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-11946"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-11946",
        "https://www.cve.org/CVERecord?id=CVE-2026-11946",
        "https://github.com/open62541/open62541/pull/8142",
        "https://github.com/open62541/open62541/commit/c9563e8ea4a8db2f64059c8ff7efe0b49a35bea3",
        "https://github.com/open62541/open62541",
        "https://github.com/open62541/open62541/pull/8142/changes/d253818d6c5e870e1db0e360b18138c8bdc809ae"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-11946",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 357960,
  "published_at": "2026-07-02T12:16:00+00:00"
}