Improper link resolution in the migration receive path in Canonical LXD versions 4.0 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client that can create instances or custom storage volumes in a project, or a malicious migration source server, to write attacker-controlled files to arbitrary paths on the target host as root, leading to full host compromise. The attacker does this with a crafted rsync or btrfs send stream that plants a symlink in the transferred volume, such as rootfs or root.img, and then writes through it.
CVE-2026-87799
“—” beside the score: it is equal to the CVSS score beside it.
This critical-severity CVE scores 9.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (35th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-88260 (ENISA EUVD)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
Upgrade to LXD versions 4.0.14, 5.0.10, 5.21.8, 6.10 or later (from the CVE record's solution, Canonical Ltd.) — apply it.
- CVSS v3
- 9.9
- EG Score
- 9.9CRITICALmedium confidence
- EG Risk
- 45EG Risk 45/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity99% × 45%Impact severity (EG Severity): CVSS 9.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.4% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: Upgrade to LXD versions 4.0.14, 5.0.10, 5.21.8, 6.10 or later (from the CVE record's solution, Canonical Ltd.). Apply it within your standard update timelines. - EPSS PROB
- 0.4%
- EPSS %ILE
- 35th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (9.9): severity, escalated by confirmed exploitation. This CVE's 9.9 is its impact severity (EG Severity), not escalated.
- EG Severity
- 9.9 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
Upgrade to LXD versions 4.0.14, 5.0.10, 5.21.8, 6.10 or later (from the CVE record's solution, Canonical Ltd.). Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
September 28, 2026
Last Modified
September 29, 2026
Advisory Details (1)
Auto-updated Oct 27, 2026Arbitrary file write on host via symlink in migration stream · Advisory · canonical/lxd · GitHub
https://github.com/canonical/lxd/security/advisories/GHSA-fmc3-3cpq-6whrAffected Packages
(2 across 2 ecosystems)
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| lxd | 5.0.2+git20231211.1364ae4-1 ... 5.0.2-6 (17 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| lxd | 5.0.2+git20231211.1364ae4-9 ... 5.0.2+git20231211.1364ae4-9+deb13u7 (8 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 14× in last 7d / 63× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
- 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-11-01 13:52 UTCEG score recompute
- 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-31 13:29 UTCEG score recompute
- 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-30 13:06 UTCEG score recompute
- 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-29 12:43 UTCEG score recompute
- 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-28 12:20 UTCEG score recompute
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-27 11:57 UTCEG score recompute
- 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-26 11:34 UTCEG score recompute
- 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-25 13:53 UTCEG score recompute
- 2026-10-25 11:12 UTCEG score recompute
- 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-24 10:49 UTCEG score recompute
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-23 10:26 UTCEG score recompute
- 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-22 10:02 UTCEG score recompute
- 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-21 09:36 UTCEG score recompute
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- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-20 09:12 UTCEG score recompute
- 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-19 08:48 UTCEG score recompute
- 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-18 03:04 UTCEG score recompute
- 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-17 07:27 UTCEG score recompute
- 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-16 07:03 UTCEG score recompute
- 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-15 05:48 UTCEG score recompute
- 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-14 01:26 UTCEG score recompute
- 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-12 21:37 UTCEG score recompute
- 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-12 14:49 UTCEG score recompute
- 2026-10-11 19:16 UTCEG score recompute
- 2026-10-11 16:33 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-11 13:49 UTCEG score recompute
- 2026-10-11 12:35 UTCEG score recompute
- 2026-10-10 23:50 UTCEG score recompute
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-09 22:31 UTCEG score recompute
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-08 21:04 UTCEG score recompute
- 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-08 02:57 UTCEG score recompute
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-06 16:39 UTCEG score recompute
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-05 19:26 UTCEG score recompute
- 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-05 02:14 UTCEG score recompute
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-03 16:24 UTCEG score recompute
- 2026-10-02 19:17 UTCEG score recompute
- 2026-10-01 22:11 UTCEG score recompute
- 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-09-30 16:37 UTCEG score recompute
- 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-09-29 17:13 UTCEG score recompute
- 2026-09-29 04:31 UTCEG score recompute
- 2026-09-29 04:00 UTCEG score recompute
- 2026-09-28 21:48 UTCEG score recompute
- 2026-09-28 17:36 UTCEG score recompute
- 2026-09-28 16:42 UTCEG score recompute
- 2026-09-28 14:24 UTCEG score recompute
- 2026-09-28 13:27 UTCEG score recomputeFirst assessed: 9.9 CRITICAL
- 2026-09-28 13:27 UTCMITRE cvelistV5first tracked
Related CVEs(same product + same CWE)
Same product
10 shownDebian:12:lxd
Frequently asked(5)
What is CVE-2026-87799?
When was CVE-2026-87799 made public?
Is CVE-2026-87799 actively exploited?
What is the CVSS score of CVE-2026-87799?
How do I remediate CVE-2026-87799?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-87799
Is Your Infrastructure Affected by CVE-2026-87799?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.