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TI-2026-26475 Aliases CVE-2026-34178GHSA-q96j-3fmm-7fv4

Importing a crafted backup leads to project restriction bypass

Priority HIGH 74CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
High
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00432 37th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed lxd (Canonical): 5.0.7, 5.21.5, 6.8.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Canonicallxd4.12.0 to before 5.0.7; 5.1.0 to before 5.21.5; 6.0.0 to before 6.8.05.0.7, 5.21.5, 6.8.0Patch availableCNA
—github.com/canonical/lxd (Go)0.0.0-20210305023314-538ac3df036e – 0.0.0-20260226085519-736f34afb267—No fix listedGHSA-q96j-3fmm-7fv4
  • lxd VendorCanonical Affected 4.12.0 to before 5.0.7; 5.1.0 to before 5.21.5; 6.0.0 to before 6.8.0 Fixed in 5.0.7, 5.21.5, 6.8.0 Patch available CNA
  • github.com/canonical/lxd (Go) Vendor— Affected 0.0.0-20210305023314-538ac3df036e – 0.0.0-20260226085519-736f34afb267 Fixed in — No fix listed GHSA-q96j-3fmm-7fv4

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*4.12 – 5.0.6; 5.21.0 – 5.21.4; 6.0 – 6.7VulnerableCanonical
  • cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:* Versions 4.12 – 5.0.6; 5.21.0 – 5.21.4; 6.0 – 6.7 Vulnerable ·Canonical

Remediation

  • Fix · CNA lxd (Canonical) Fixed in 5.0.7, 5.21.5, 6.8.0

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Canonical lxd 5.0.7, 5.21.5, 6.8.0

    3 records Highest priority Priority HIGH 3 HIGH

    Other records, highest priority first

    • TI-2026-26476 Update of type field in restricted TLS certificate allows privilege escalation to cluster adminPriority HIGH 74
    • TI-2026-26474 VM lowlevel restriction bypass via raw.apparmor and raw.qemu.confPriority HIGH 74
    Show all 3 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34178
  2. 2026-10-03 Alias added: GHSA-q96j-3fmm-7fv4
  3. 2026-10-25 EPSS moved to the below the 50th percentile

References

Exploit 1

Patch 1

Advisory 1

Other 1

  • TI-2026-22659 Authenticated RCE via unsanitized compression_algorithm CVSS 4.0CRITICAL 9.4
  • TI-2026-47475 Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE CVSS 3.1CRITICAL 9.9
  • TI-2026-45146 Cross-project instance move bypasses all project restrictions allowing host command execution CVSS 3.1CRITICAL 9.9
  • TI-2026-45143 Cross-project instance copy bypasses target project restrictions via TOCTOU in config merge CVSS 3.1CRITICAL 9.9
  • TI-2026-45142 Project restriction bypass via instance migration config override CVSS 3.1CRITICAL 9.9
  • TI-2026-45140 Root RCE via image backup.yaml symlink CVSS 3.1CRITICAL 9.9
See all 34 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences