CVE-2026-85526
Path traversal in the Btrfs storage driver (unpackVolume) in Canonical LXD on Linux allows an authenticated user with instance creation privileges to delete or replace arbitrary files and directories on the host filesystem as root via a crafted subvolumes[].path entry in backup/optimized_header.yaml during a btrfs optimized backup import.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Puntuación base: 9.9
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.52%
- Percentil entre todas las CVEs puntuadas: 42
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1210Exploitation of Remote Serviceslateral movement75 % - Impacto principal
T1565.001Stored Data Manipulationimpact85 % - Impacto secundario
T1070.004File Deletionstealth80 %
Explotación de servicio remoto (LXD) por usuario autenticado con privilegios. El path traversal en backup import permite manipular/eliminar archivos del host como root (integridad de datos).
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-22
Referencias
- https://github.com/canonical/lxd-private/pull/103
- https://github.com/canonical/lxd-private/pull/104
- https://github.com/canonical/lxd-private/pull/105
- https://github.com/canonical/lxd-private/pull/84
- https://github.com/canonical/lxd-private/pull/87
- https://github.com/canonical/lxd/security/advisories/GHSA-h85r-gjgx-g2rv
JSON original (NVD)
Mostrar
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"affected": [
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"lastModified": "2026-09-29T04:18:00.690",
"sourceIdentifier": "security@ubuntu.com"
}