---
title: "CVE-2026-34178: LXD: Importing a crafted backup leads to project restriction bypass"
url: https://erroneo.us/security/cve/CVE-2026-34178/
description: "CVE-2026-34178 (github.com/canonical/lxd (Go)): In Canonical LXD before 6.8, the backup import path validates project restrictions against backup/index.yaml…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-04-09
date_modified: 2026-04-10
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-34178"
kev: false
cvss: 9.1
epss: 0.00675
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-34178: LXD: Importing a crafted backup leads to project restriction bypass

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.7% , percentile 52: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 52% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Needs an account (high (admin)). Exposure depends on who can log in.
- Only applies if your dependency tree includes github.com/canonical/lxd (Go) >= 0.0.0-20210305023314-538ac3df036e, <= 0.0.0-20260226085519-736f34afb267, no fixed version listed . Check your lockfile, including transitive dependencies.

## What it is

In Canonical LXD before 6.8, the backup import path validates project restrictions against backup/index.yaml in the supplied tar archive but creates the instance from backup/container/backup.yaml, a separate file in the same archive that is never checked against project restrictions. An authenticated remote attacker with instance-creation permission in a restricted project can craft a backup archive where backup.yaml carries restricted settings such as security.privileged=true or raw.lxc directives, bypassing all project restriction enforcement and allowing full host compromise.

## Affected packages

- Go `github.com/canonical/lxd` >= 0.0.0-20210305023314-538ac3df036e, <= 0.0.0-20260226085519-736f34afb267 → fixed: none listed

## Affected products (CVE record)

- Canonical lxd: 4.12.0 < 5.0.7, 5.1.0 < 5.21.5, 6.0.0 < 6.8.0

## Severity

- canonical CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.68% probability of exploitation activity in the next 30 days; percentile 52.

## Sources

- [Importing a crafted backup leads to project restriction bypass](https://github.com/canonical/lxd/security/advisories/GHSA-q96j-3fmm-7fv4)
- [Import: Create backup config from index](https://github.com/canonical/lxd/pull/17921)
- [GitHub Advisory GHSA-q96j-3fmm-7fv4](https://github.com/advisories/GHSA-q96j-3fmm-7fv4)
- [CVE.org record CVE-2026-34178](https://www.cve.org/CVERecord?id=CVE-2026-34178)
- [NVD entry CVE-2026-34178](https://nvd.nist.gov/vuln/detail/CVE-2026-34178)

---
Source page: https://erroneo.us/security/cve/CVE-2026-34178/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt