UBUNTU-CVE-2026-47766 (CVE-2026-47766)

Vulnerability from osv_ubuntu – Published: 2026-08-14 17:18 – Updated: 2026-08-19 11:05 – Source website
VLAI
Details

crun is an open source OCI Container Runtime fully written in C. Prior to version 1.28, crun's default device setup opens the container rootfs /dev directory without O_NOFOLLOW. If an OCI bundle contains rootfs/dev as a symlink and the bundle configuration does not mount /dev, crun follows that symlink and creates the default device nodes and stdio symlinks at the symlink target outside the container rootfs. In a local rootful crun replay, this created fixed device nodes and symlinks outside the rootfs before crun returned failure. A pre-existing file named ptmx in the target directory was also replaced by crun's forced ptmx -> pts/ptmx symlink. Version 1.28 fixes the issue.

Severity
5.1 (Medium)
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "crun",
            "binary_version": "0.12.1+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "crun",
        "purl": "pkg:deb/ubuntu/crun@0.12.1+dfsg-1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.10.5+dfsg-1",
        "0.10.6+dfsg-1",
        "0.11+dfsg-1",
        "0.12+dfsg-1",
        "0.12.1+dfsg-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "crun",
            "binary_version": "0.17+dfsg-1.1ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "crun",
        "purl": "pkg:deb/ubuntu/crun@0.17+dfsg-1.1ubuntu0.1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.17+dfsg-1",
        "0.17+dfsg-1.1",
        "0.17+dfsg-1.1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "crun",
            "binary_version": "1.14.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "crun",
        "purl": "pkg:deb/ubuntu/crun@1.14.1-1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.5-1",
        "1.11-1",
        "1.11.1-1",
        "1.12-1",
        "1.13-1",
        "1.14-1",
        "1.14.1-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "crun",
            "binary_version": "1.21-1ubuntu2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "crun",
        "purl": "pkg:deb/ubuntu/crun@1.21-1ubuntu2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.20-1syncable1",
        "1.21-1ubuntu2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "crun",
            "binary_version": "1.21-1ubuntu3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "crun",
        "purl": "pkg:deb/ubuntu/crun@1.21-1ubuntu3?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.21-1ubuntu2",
        "1.21-1ubuntu3"
      ]
    }
  ],
  "aliases": [],
  "details": "crun is an open source OCI Container Runtime fully written in C. Prior to version 1.28, crun\u0027s default device setup opens the container rootfs `/dev` directory without `O_NOFOLLOW`. If an OCI bundle contains `rootfs/dev` as a symlink and the bundle configuration does not mount `/dev`, crun follows that symlink and creates the default device nodes and stdio symlinks at the symlink target outside the container rootfs. In a local rootful crun replay, this created fixed device nodes and symlinks outside the rootfs before crun returned failure. A pre-existing file named `ptmx` in the target directory was also replaced by crun\u0027s forced `ptmx -\u003e pts/ptmx` symlink. Version 1.28 fixes the issue.",
  "id": "UBUNTU-CVE-2026-47766",
  "modified": "2026-08-19T11:05:27Z",
  "published": "2026-08-14T17:18:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-47766"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-47766"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/containers/crun/security/advisories/GHSA-7vwr-4279-7gq5"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/containers/crun/commit/c6f338ac2e26e216ab7820b91863a0b84e608097"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-47766"
  ]
}



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