Vulnerability-Lookup

UBUNTU-CVE-2026-87799 (CVE-2026-87799)

Vulnerability from osv_ubuntu – Published: 2026-09-28 14:17 – Updated: 2026-09-30 21:35 – Source website

Details

Improper link resolution in the migration receive path in Canonical LXD versions 4.0 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client that can create instances or custom storage volumes in a project, or a malicious migration source server, to write attacker-controlled files to arbitrary paths on the target host as root, leading to full host compromise. The attacker does this with a crafted rsync or btrfs send stream that plants a symlink in the transferred volume, such as rootfs or root.img, and then writes through it.

Severity

9.9 (Critical)


                    
                      CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-87799	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-87799	REPORT
	https://github.com/canonical/lxd/security/advisor…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "golang-github-lxc-lxd-dev",
            "binary_version": "2.0.11-0ubuntu1~16.04.4+esm3"
          },
          {
            "binary_name": "lxc2",
            "binary_version": "2.0.11-0ubuntu1~16.04.4+esm3"
          },
          {
            "binary_name": "lxd",
            "binary_version": "2.0.11-0ubuntu1~16.04.4+esm3"
          },
          {
            "binary_name": "lxd-client",
            "binary_version": "2.0.11-0ubuntu1~16.04.4+esm3"
          },
          {
            "binary_name": "lxd-tools",
            "binary_version": "2.0.11-0ubuntu1~16.04.4+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "lxd",
        "purl": "pkg:deb/ubuntu/lxd@2.0.11-0ubuntu1~16.04.4+esm3?arch=source\u0026distro=esm-infra-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.20-0ubuntu4",
        "0.21-0ubuntu3",
        "0.21-0ubuntu5",
        "0.22-0ubuntu1",
        "0.22-0ubuntu2",
        "0.23-0ubuntu1",
        "0.23-0ubuntu2",
        "0.23-0ubuntu3",
        "0.24-0ubuntu2",
        "0.24-0ubuntu3",
        "0.24-0ubuntu4",
        "0.25-0ubuntu1",
        "0.26-0ubuntu2",
        "0.26-0ubuntu3",
        "0.27-0ubuntu1",
        "0.27-0ubuntu2",
        "2.0.0~beta1-0ubuntu3",
        "2.0.0~beta1-0ubuntu4",
        "2.0.0~beta2-0ubuntu1",
        "2.0.0~beta2-0ubuntu2",
        "2.0.0~beta3-0ubuntu1",
        "2.0.0~beta3-0ubuntu2",
        "2.0.0~beta3-0ubuntu3",
        "2.0.0~beta3-0ubuntu4",
        "2.0.0~beta4-0ubuntu1",
        "2.0.0~beta4-0ubuntu2",
        "2.0.0~beta4-0ubuntu3",
        "2.0.0~beta4-0ubuntu4",
        "2.0.0~beta4-0ubuntu5",
        "2.0.0~beta4-0ubuntu6",
        "2.0.0~beta4-0ubuntu7",
        "2.0.0~rc1-0ubuntu1",
        "2.0.0~rc1-0ubuntu2",
        "2.0.0~rc1-0ubuntu3",
        "2.0.0~rc2-0ubuntu2",
        "2.0.0~rc2-0ubuntu3",
        "2.0.0~rc3-0ubuntu1",
        "2.0.0~rc3-0ubuntu2",
        "2.0.0~rc3-0ubuntu3",
        "2.0.0~rc3-0ubuntu4",
        "2.0.0~rc4-0ubuntu1",
        "2.0.0~rc5-0ubuntu1",
        "2.0.0~rc6-0ubuntu1",
        "2.0.0~rc6-0ubuntu2",
        "2.0.0~rc7-0ubuntu1",
        "2.0.0~rc7-0ubuntu2",
        "2.0.0~rc8-0ubuntu1",
        "2.0.0~rc8-0ubuntu2",
        "2.0.0~rc8-0ubuntu3",
        "2.0.0~rc8-0ubuntu5",
        "2.0.0~rc8-0ubuntu6",
        "2.0.0~rc8-0ubuntu7",
        "2.0.0~rc9-0ubuntu2",
        "2.0.0~rc9-0ubuntu3",
        "2.0.0~rc9-0ubuntu4",
        "2.0.0~rc9-0ubuntu5",
        "2.0.0-0ubuntu1",
        "2.0.0-0ubuntu2",
        "2.0.0-0ubuntu3",
        "2.0.0-0ubuntu4",
        "2.0.1-0ubuntu1~16.04.1",
        "2.0.2-0ubuntu1~16.04.1",
        "2.0.3-0ubuntu1~ubuntu16.04.2",
        "2.0.4-0ubuntu1~ubuntu16.04.1",
        "2.0.5-0ubuntu1~ubuntu16.04.1",
        "2.0.8-0ubuntu1~ubuntu16.04.1",
        "2.0.8-0ubuntu1~ubuntu16.04.2",
        "2.0.9-0ubuntu1~16.04.1",
        "2.0.9-0ubuntu1~16.04.2",
        "2.0.10-0ubuntu1~16.04.1",
        "2.0.10-0ubuntu1~16.04.2",
        "2.0.11-0ubuntu1~16.04.2",
        "2.0.11-0ubuntu1~16.04.4",
        "2.0.11-0ubuntu1~16.04.4+esm1",
        "2.0.11-0ubuntu1~16.04.4+esm2",
        "2.0.11-0ubuntu1~16.04.4+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "lxd",
            "binary_version": "3.0.3-0ubuntu1~18.04.2+esm3"
          },
          {
            "binary_name": "lxd-client",
            "binary_version": "3.0.3-0ubuntu1~18.04.2+esm3"
          },
          {
            "binary_name": "lxd-tools",
            "binary_version": "3.0.3-0ubuntu1~18.04.2+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "lxd",
        "purl": "pkg:deb/ubuntu/lxd@3.0.3-0ubuntu1~18.04.2+esm3?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.18-0ubuntu6",
        "2.19-0ubuntu1",
        "2.20-0ubuntu3",
        "2.20-0ubuntu4",
        "2.21-0ubuntu1",
        "2.21-0ubuntu2",
        "2.21-0ubuntu3",
        "2.21-0ubuntu4",
        "3.0.0~beta2-0ubuntu3",
        "3.0.0~beta3-0ubuntu3",
        "3.0.0~beta5-0ubuntu2",
        "3.0.0~beta7-0ubuntu1",
        "3.0.0-0ubuntu1",
        "3.0.0-0ubuntu2",
        "3.0.0-0ubuntu3",
        "3.0.0-0ubuntu4",
        "3.0.1-0ubuntu1~18.04.1",
        "3.0.2-0ubuntu1~18.04.1",
        "3.0.3-0ubuntu1~18.04.1",
        "3.0.3-0ubuntu1~18.04.2",
        "3.0.3-0ubuntu1~18.04.2+esm1",
        "3.0.3-0ubuntu1~18.04.2+esm2",
        "3.0.3-0ubuntu1~18.04.2+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "lxd",
            "binary_version": "1:0.10"
          },
          {
            "binary_name": "lxd-client",
            "binary_version": "1:0.10"
          },
          {
            "binary_name": "lxd-tools",
            "binary_version": "1:0.10"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "lxd",
        "purl": "pkg:deb/ubuntu/lxd@1:0.10?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:0.7",
        "1:0.8",
        "1:0.9",
        "1:0.10"
      ]
    }
  ],
  "aliases": [],
  "details": "Improper link resolution in the migration receive path in Canonical LXD versions 4.0 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client that can create instances or custom storage volumes in a project, or a malicious migration source server, to write attacker-controlled files to arbitrary paths on the target host as root, leading to full host compromise. The attacker does this with a crafted rsync or btrfs send stream that plants a symlink in the transferred volume, such as rootfs or root.img, and then writes through it.",
  "id": "UBUNTU-CVE-2026-87799",
  "modified": "2026-09-30T21:35:22Z",
  "published": "2026-09-28T14:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-87799"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-87799"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/canonical/lxd/security/advisories/GHSA-fmc3-3cpq-6whr"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-87799"
  ]
}

CVE-2026-87799 (GCVE-0-2026-87799)

Vulnerability from cvelistv5 – Published: 2026-09-28 13:22 – Updated: 2026-09-29 03:55

Title

Arbitrary file write on LXD host via symlink in migration stream

Summary

Severity

9.9 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-28 00:00 UTC

CWE

CWE-59 - Improper link resolution before file access ('link following')

Assigner

canonical mitre root Scorecard

References

1 reference

URL	Tags
https://github.com/canonical/lxd/security/advisor…	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
Canonical	LXD	Affected: 4.0.0 , < 4.0.14 (semver) Affected: 5.0.0 , < 5.0.10 (semver) Affected: 5.21.0 , < 5.21.8 (semver) Affected: 6.0 , < 6.10 (semver)

Date Public

2026-09-25 03:00

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-87799",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-28T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-29T03:55:19.115Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageName": "LXD",
          "platforms": [
            "Linux"
          ],
          "product": "LXD",
          "repo": "https://github.com/canonical/lxd",
          "vendor": "Canonical",
          "versions": [
            {
              "lessThan": "4.0.14",
              "status": "affected",
              "version": "4.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "5.0.10",
              "status": "affected",
              "version": "5.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "5.21.8",
              "status": "affected",
              "version": "5.21.0",
              "versionType": "semver"
            },
            {
              "lessThan": "6.10",
              "status": "affected",
              "version": "6.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "datePublic": "2026-09-25T03:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Improper link resolution in the migration receive path in Canonical LXD versions 4.0 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client that can create instances or custom storage volumes in a project, or a malicious migration source server, to write attacker-controlled files to arbitrary paths on the target host as root, leading to full host compromise. The attacker does this with a crafted rsync or btrfs send stream that plants a symlink in the transferred volume, such as rootfs or root.img, and then writes through it."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-132",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-132 Symlink Attack"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.9,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-59",
              "description": "CWE-59 Improper link resolution before file access (\u0027link following\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-28T13:22:29.148Z",
        "orgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc",
        "shortName": "canonical"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/canonical/lxd/security/advisories/GHSA-fmc3-3cpq-6whr"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to LXD versions 4.0.14, 5.0.10, 5.21.8, 6.10 or later."
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Arbitrary file write on LXD host via symlink in migration stream"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc",
    "assignerShortName": "canonical",
    "cveId": "CVE-2026-87799",
    "datePublished": "2026-09-28T13:22:29.148Z",
    "dateReserved": "2026-09-09T10:00:46.383Z",
    "dateUpdated": "2026-09-29T03:55:19.115Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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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.

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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Action not permitted

UBUNTU-CVE-2026-87799 (CVE-2026-87799)

CVE-2026-87799 (GCVE-0-2026-87799)

Tags

Sightings

Nomenclature

Related by attack behaviour