CVE-2026-66898

CRITICALPre-NVD 9.99.9—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 73% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
9.9EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.9Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.

CVSS v3
9.9
EG Score
9.9(medium)
EG Risk
61(Track*)
EG Risk 61/100SSVC: Track*

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity99% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
27%
KEV
Not listed

Published

August 12, 2026

Last Modified

August 28, 2026

Advisory Details (1)

Auto-updated Aug 28, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE · Advisory · canonical/lxd · GitHub

https://github.com/canonical/lxd/security/advisories/GHSA-m857-c7gc-c984

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 35× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 04:30 UTCEG score recompute
  2. 2026-08-30 01:22 UTCEPSS rescore
  3. 2026-08-29 08:31 UTCEG score recompute
  4. 2026-08-28 21:42 UTCEPSS rescore
  5. 2026-08-27 15:15 UTCEG score recompute
  6. 2026-08-26 18:48 UTCEG score recompute
  7. 2026-08-26 14:47 UTCEPSS rescore
  8. 2026-08-25 17:28 UTCEG score recompute
  9. 2026-08-25 13:49 UTCEPSS rescore
  10. 2026-08-24 17:16 UTCEG score recompute
  11. 2026-08-24 13:06 UTCEG score recompute
  12. 2026-08-23 01:36 UTCEG score recompute
  13. 2026-08-23 00:19 UTCEPSS rescore
  14. 2026-08-22 01:51 UTCEG score recompute
  15. 2026-08-21 23:49 UTCEPSS rescore
  16. 2026-08-21 02:08 UTCEG score recompute
  17. 2026-08-20 22:56 UTCEPSS rescore
  18. 2026-08-19 18:34 UTCEG score recompute
  19. 2026-08-19 17:04 UTCEPSS rescore
  20. 2026-08-18 17:15 UTCEG score recompute
  21. 2026-08-18 13:48 UTCEPSS rescore
  22. 2026-08-17 17:13 UTCEG score recompute
  23. 2026-08-17 13:47 UTCEPSS rescore
  24. 2026-08-16 17:21 UTCEG score recompute
  25. 2026-08-16 14:56 UTCEPSS rescore
Show 10 more
  1. 2026-08-16 05:31 UTCEG score recompute
  2. 2026-08-15 01:53 UTCEG score recompute
  3. 2026-08-15 01:30 UTCEPSS rescore
  4. 2026-08-13 22:18 UTCEG score recompute
  5. 2026-08-13 22:00 UTCEPSS rescore
  6. 2026-08-13 14:24 UTCEG score recompute
  7. 2026-08-13 13:56 UTCEG score recompute
  8. 2026-08-12 21:20 UTCEG score recompute
  9. 2026-08-12 20:26 UTCEG score recompute
  10. 2026-08-12 20:25 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-66898?
CVE-2026-66898 is a critical vulnerability published on August 12, 2026. A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit…
When was CVE-2026-66898 disclosed?
CVE-2026-66898 was first published in the National Vulnerability Database on August 12, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66898 actively exploited?
CVE-2026-66898 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 72.9% of all scored CVEs.
What is the CVSS score of CVE-2026-66898?
CVE-2026-66898 has a CVSS v3 base score of 9.9 (NVD).
How do I remediate CVE-2026-66898?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66898, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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