Vulnerability-Lookup

ubuntu-cve-2026-23954

Vulnerability from osv_ubuntu

Published

2026-01-22 22:16

Modified

2026-07-02 16:11

Summary

Details

Incus is a system container and virtual machine manager. Versions 6.21.0 and below allow a user with the ability to launch a container with a custom image (e.g a member of the ‘incus’ group) to use directory traversal or symbolic links in the templating functionality to achieve host arbitrary file read, and host arbitrary file write. This ultimately results in arbitrary command execution on the host. When using an image with a metadata.yaml containing templates, both the source and target paths are not checked for symbolic links or directory traversal. This can also be exploited in IncusOS. A fix is planned for versions 6.0.6 and 6.21.0, but they have not been released at the time of publication.

Severity

8.7 (High)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-23954	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-23954	REPORT
	https://github.com/lxc/incus/security/advisories/…	REPORT
	https://github.com/lxc/incus/blob/HEAD/internal/s…	REPORT
	https://github.com/lxc/incus/blob/HEAD/internal/s…	REPORT
	https://github.com/user-attachments/files/2447359…	REPORT
	https://github.com/user-attachments/files/2447360…	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"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "golang-github-lxc-incus-dev",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
          },
          {
            "binary_name": "incus",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
          },
          {
            "binary_name": "incus-agent",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
          },
          {
            "binary_name": "incus-client",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
          },
          {
            "binary_name": "incus-migrate",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
          },
          {
            "binary_name": "incus-tools",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "incus",
        "purl": "pkg:deb/ubuntu/incus@6.0.0-1ubuntu0.3+esm3?arch=source\u0026distro=esm-apps/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.4-1ubuntu1",
        "0.5.1-1",
        "0.5.1-3",
        "0.6-1",
        "6.0.0-1",
        "6.0.0-1ubuntu0.1",
        "6.0.0-1ubuntu0.2",
        "6.0.0-1ubuntu0.2+esm1",
        "6.0.0-1ubuntu0.3",
        "6.0.0-1ubuntu0.3+esm1",
        "6.0.0-1ubuntu0.3+esm2",
        "6.0.0-1ubuntu0.3+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "golang-github-lxc-incus-dev",
            "binary_version": "6.0.4-2"
          },
          {
            "binary_name": "incus",
            "binary_version": "6.0.4-2"
          },
          {
            "binary_name": "incus-agent",
            "binary_version": "6.0.4-2"
          },
          {
            "binary_name": "incus-base",
            "binary_version": "6.0.4-2"
          },
          {
            "binary_name": "incus-client",
            "binary_version": "6.0.4-2"
          },
          {
            "binary_name": "incus-extra",
            "binary_version": "6.0.4-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "incus",
        "purl": "pkg:deb/ubuntu/incus@6.0.4-2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "6.0.3-4",
        "6.0.4-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "golang-github-lxc-incus-dev",
            "binary_version": "6.0.5-8ubuntu0.26.04.1~esm1"
          },
          {
            "binary_name": "incus",
            "binary_version": "6.0.5-8ubuntu0.26.04.1~esm1"
          },
          {
            "binary_name": "incus-agent",
            "binary_version": "6.0.5-8ubuntu0.26.04.1~esm1"
          },
          {
            "binary_name": "incus-base",
            "binary_version": "6.0.5-8ubuntu0.26.04.1~esm1"
          },
          {
            "binary_name": "incus-client",
            "binary_version": "6.0.5-8ubuntu0.26.04.1~esm1"
          },
          {
            "binary_name": "incus-extra",
            "binary_version": "6.0.5-8ubuntu0.26.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:26.04:LTS",
        "name": "incus",
        "purl": "pkg:deb/ubuntu/incus@6.0.5-8ubuntu0.26.04.1~esm1?arch=source\u0026distro=esm-apps/resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "6.0.4-2",
        "6.0.5-8",
        "6.0.5-8ubuntu0.26.04.1~esm1"
      ]
    }
  ],
  "aliases": [],
  "details": "Incus is a system container and virtual machine manager. Versions 6.21.0 and below allow a user with the ability to launch a container with a custom image (e.g a member of the \u2018incus\u2019 group) to use directory traversal or symbolic links in the templating functionality to achieve host arbitrary file read, and host arbitrary file write. This ultimately results in arbitrary command execution on the host. When using an image with a metadata.yaml containing templates, both the source and target paths are not checked for symbolic links or directory traversal. This can also be exploited in IncusOS. A fix is planned for versions 6.0.6 and 6.21.0, but they have not been released at the time of publication.",
  "id": "UBUNTU-CVE-2026-23954",
  "modified": "2026-07-02T16:11:56Z",
  "published": "2026-01-22T22:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-23954"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-23954"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/lxc/incus/security/advisories/GHSA-7f67-crqm-jgh7"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7215"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7294"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/user-attachments/files/24473599/template_arbitrary_write.sh"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/user-attachments/files/24473601/templates_arbitrary_write.patch"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-23954"
  ]
}

CVE-2026-23954 (GCVE-0-2026-23954)

Vulnerability from cvelistv5 – Published: 2026-01-22 21:45 – Updated: 2026-01-26 21:02

Title

Incus container image templating arbitrary host file read and write

Summary

Severity

8.7 (High)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-01-26 21:02 UTC

CWE

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/lxc/incus/security/advisories/…	x_refsource_CONFIRM
https://github.com/lxc/incus/blob/HEAD/internal/s…	x_refsource_MISC
https://github.com/lxc/incus/blob/HEAD/internal/s…	x_refsource_MISC
https://github.com/user-attachments/files/2447359…	x_refsource_MISC
https://github.com/user-attachments/files/2447360…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
lxc	incus	Affected: >= 6.1.0, <= 6.20.0 Affected: <= 6.0.5

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-23954",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-26T21:02:38.599423Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-01-26T21:02:48.738Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "incus",
          "vendor": "lxc",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 6.1.0, \u003c= 6.20.0"
            },
            {
              "status": "affected",
              "version": "\u003c= 6.0.5"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Incus is a system container and virtual machine manager. Versions 6.21.0 and below allow a user with the ability to launch a container with a custom image (e.g a member of the \u2018incus\u2019 group) to use directory traversal or symbolic links in the templating functionality to achieve host arbitrary file read, and host arbitrary file write. This ultimately results in arbitrary command execution on the host. When using an image with a metadata.yaml containing templates, both the source and target paths are not checked for symbolic links or directory traversal. This can also be exploited in IncusOS. A fix is planned for versions 6.0.6 and 6.21.0, but they have not been released at the time of publication."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "ADJACENT_NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-22",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-01-22T21:45:55.696Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/lxc/incus/security/advisories/GHSA-7f67-crqm-jgh7",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/lxc/incus/security/advisories/GHSA-7f67-crqm-jgh7"
        },
        {
          "name": "https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7215",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7215"
        },
        {
          "name": "https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7294",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/lxc/incus/blob/HEAD/internal/server/instance/drivers/driver_lxc.go#L7294"
        },
        {
          "name": "https://github.com/user-attachments/files/24473599/template_arbitrary_write.sh",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/user-attachments/files/24473599/template_arbitrary_write.sh"
        },
        {
          "name": "https://github.com/user-attachments/files/24473601/templates_arbitrary_write.patch",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/user-attachments/files/24473601/templates_arbitrary_write.patch"
        }
      ],
      "source": {
        "advisory": "GHSA-7f67-crqm-jgh7",
        "discovery": "UNKNOWN"
      },
      "title": "Incus container image templating arbitrary host file read and write"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-23954",
    "datePublished": "2026-01-22T21:45:55.696Z",
    "dateReserved": "2026-01-19T14:49:06.312Z",
    "dateUpdated": "2026-01-26T21:02:48.738Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
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.

Detection rules are retrieved from Rulezet.

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.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.