GHSA-83XR-5XXR-MH92

Vulnerability from github – Published: 2026-03-27 17:17 – Updated: 2026-03-27 17:17
VLAI?
Summary
Incus vulnerable to arbitrary file read and write through pongo templates
Details

Summary

Instance template files can be used to cause arbitrary read or writes as root on the host server.

Details

Incus allows for pongo2 templates within instances which can be used at various times in the instance lifecycle to template files inside of the instance. This particular implementation of pongo2 within Incus allowed for file read/write but with the expectation that the pongo2 chroot feature would isolate all such access to the instance's filesystem.

This was allowed such that a template could theoretically read a file and then generate a new version of said file.

Unfortunately the chroot isolation mechanism is entirely skipped by pongo2 leading to easy access to the entire system's filesystem with root privileges.

Credit

This issue was discovered and reported by the team at 7asecurity

Severity ?
9.9 (Critical)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/lxc/incus/v6"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.23.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/lxc/incus"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "0.7.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33897"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1336"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-27T17:17:03Z",
    "nvd_published_at": "2026-03-26T23:16:20Z",
    "severity": "CRITICAL"
  },
  "details": "### Summary\nInstance template files can be used to cause arbitrary read or writes as root on the host server.\n\n### Details\nIncus allows for pongo2 templates within instances which can be used at various times in the instance lifecycle to template files inside of the instance. This particular implementation of pongo2 within Incus allowed for file read/write but with the expectation that the pongo2 chroot feature would isolate all such access to the instance\u0027s filesystem.\n\nThis was allowed such that a template could theoretically read a file and then generate a new version of said file.\n\nUnfortunately the chroot isolation mechanism is entirely skipped by pongo2 leading to easy access to the entire system\u0027s filesystem with root privileges.\n\n### Credit\nThis issue was discovered and reported by the team at [7asecurity](https://7asecurity.com/)",
  "id": "GHSA-83xr-5xxr-mh92",
  "modified": "2026-03-27T17:17:03Z",
  "published": "2026-03-27T17:17:03Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/lxc/incus/security/advisories/GHSA-83xr-5xxr-mh92"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33897"
    },
    {
      "type": "WEB",
      "url": "https://github.com/lxc/incus/commit/487edf5984fad89b0f762c03a7e211fdd38396fb"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/lxc/incus"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Incus vulnerable to arbitrary file read and write through pongo templates"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

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.