FKIE_CVE-2026-34177

Vulnerability from fkie_nvd - Published: 2026-04-09 10:16 - Updated: 2026-04-22 20:57
Severity
9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Summary
Canonical LXD versions 4.12 through 6.7 contain an incomplete denylist in isVMLowLevelOptionForbidden (lxd/project/limits/permissions.go), which omits raw.apparmor and raw.qemu.conf from the set of keys blocked under the restricted.virtual-machines.lowlevel=block project restriction. A remote attacker with can_edit permission on a VM instance in a restricted project can inject an AppArmor rule and a QEMU chardev configuration that bridges the LXD Unix socket into the guest VM, enabling privilege escalation to LXD cluster administrator and subsequently to host root.
References
security@ubuntu.comhttps://github.com/canonical/lxd/pull/17909Issue Tracking
security@ubuntu.comhttps://github.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6fThird Party Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6fThird Party Advisory
Impacted products
Vendor Product Version
canonical lxd *
canonical lxd *
canonical lxd *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "41A5CC7C-00BE-436D-957A-4636E52D0DF1",
              "versionEndIncluding": "5.0.6",
              "versionStartIncluding": "4.12",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "92A82DF4-3ED9-47E0-BDF1-DB9138EE0883",
              "versionEndIncluding": "5.21.4",
              "versionStartIncluding": "5.21.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "5C28FC63-0BE4-4B40-A87F-DF242AE33303",
              "versionEndIncluding": "6.7",
              "versionStartIncluding": "6.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Canonical LXD versions 4.12 through 6.7 contain an incomplete denylist in isVMLowLevelOptionForbidden (lxd/project/limits/permissions.go), which omits raw.apparmor and raw.qemu.conf from the set of keys blocked under the restricted.virtual-machines.lowlevel=block project restriction. A remote attacker with can_edit permission on a VM instance in a restricted project can inject an AppArmor rule and a QEMU chardev configuration that bridges the LXD Unix socket into the guest VM, enabling privilege escalation to LXD cluster administrator and subsequently to host root."
    }
  ],
  "id": "CVE-2026-34177",
  "lastModified": "2026-04-22T20:57:22.520",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "HIGH",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.3,
        "impactScore": 6.0,
        "source": "security@ubuntu.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-04-09T10:16:21.653",
  "references": [
    {
      "source": "security@ubuntu.com",
      "tags": [
        "Issue Tracking"
      ],
      "url": "https://github.com/canonical/lxd/pull/17909"
    },
    {
      "source": "security@ubuntu.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6f"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6f"
    }
  ],
  "sourceIdentifier": "security@ubuntu.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-184"
        }
      ],
      "source": "security@ubuntu.com",
      "type": "Secondary"
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.