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Windows Spaceport.sys CVE-2026-70102

| EUVDEUVD-2026-99679 HIGH
Use After Free (CWE-416)
2026-10-13 secure@microsoft.com GHSA-h8vp-8jwv-9hv9
7.8
CVSS 3.1 · Vendor: microsoft
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Gain low-privileged authenticated access
  2. Delivery
    Invoke vulnerable Spaceport.sys code path
  3. Exploit
    Trigger use-after-free in kernel
  4. Execution
    Corrupt kernel object/memory
  5. Impact
    Elevate to SYSTEM privileges

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Memory lifecycle management
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Requires the attacker to already have authenticated, low-privileged local code execution on a Windows host where the Storage Spaces driver (Spaceport.sys) is present and loadable - which is the default on all supported Windows 10, Windows 11, and Windows Server editions listed. No user interaction is needed (UI:N) and complexity is low (AC:L), but exploitation is strictly local (AV:L): there is no remote or network-triggerable path, so the flaw cannot be reached by an unauthenticated or purely remote attacker. The principal limiting factor is this pre-existing local foothold requirement; applying the vendor patch (builds at or above the EUVD-listed fixed versions, e.g. 10.0.26100.9711 for 24H2) removes the condition.

Impact

This is a genuine but second-tier priority. The CVSS vector (AV:L/AC:L/PR:L/UI:N) describes a local, low-complexity privilege-escalation flaw in the Windows Storage Spaces driver (Spaceport.sys) that an already-authenticated low-privileged user can trigger to gain SYSTEM-level control (C:H/I:H/A:H), consistent with CWE-416 use-after-free kernel corruption. The signals are internally consistent but point AWAY from urgency: CISA's SSVC decision shows Exploitation=none and Automatable=no, meaning no observed exploitation and no mass/wormable path, while Technical Impact=total aligns with the full CIA impact. There is no CISA KEV listing and no POC referenced in the data, so this is not confirmed exploited. The main limiter is the local attack vector - an attacker must already have code execution as an authenticated user on the host, so this is a post-compromise escalation primitive rather than an initial-access or remotely wormable bug. EPSS is not provided in the input and cannot be cited. Net: real and patch-worthy (especially on multi-user or shared Windows hosts), but not a drop-everything emergency absent exploitation evidence.

Exploit ScenarioDerived

A low-privileged but authenticated user (or malware already running in a limited user context) executes a crafted local program that drives Spaceport.sys into a use-after-free condition, corrupting kernel memory to elevate to SYSTEM. No public exploit code is identified at time of analysis, and the low attack complexity (AC:L) means a reliable exploit, once written, would require no special timing or configuration.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.3% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 14, 2026

Local privilege escalation in the Microsoft Windows Storage Spaces driver (Spaceport.sys) lets an authenticated, low-privileged attacker who already has code execution on a host corrupt kernel memory and obtain SYSTEM-level rights. The defect is a use-after-free (CWE-416) that is locally reachable with low attack complexity and no user interaction, and it affects Windows 10, Windows 11 and Windows Server builds below the fixed versions enumerated in the vendor update. No public exploit code has been identified and CISA's SSVC decision data records no exploitation activity, so this is a genuine but second-tier patching priority relative to any actively exploited issue in the same release cycle.

RemediationAI

Vendor-released patch: Microsoft has published fixed builds in its monthly update for every affected branch - apply the update that brings each host to or above 10.0.17763.9376 (Windows 10 1809 and Server 2019/Server Core), 10.0.19044.7807 (Windows 10 21H2 and 22H2), 10.0.20348.5761 (Server 2022), 10.0.22631.7652 (Windows 11 23H2), 10.0.26100.9711 (Windows 11 24H2), 10.0.26200.9711 (Windows 11 25H2), 10.0.28000.3231 (Windows 11 26H1), 10.0.26300.9711 (Windows 11 26H2), or 10.0.26100.33650 (Server 2025 and Server Core), per the MSRC advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70102. Because the vector is local (AV:L, PR:L, UI:N) with no remote or network-triggerable path and no public exploit code identified, patch scheduling can be risk-ranked rather than emergency: prioritise multi-session and RDP-accessible hosts, Terminal Server/Citrix-style estates, VDI, and any host where Storage Spaces is actually in use, since privilege escalation here only matters once an attacker already holds authenticated low-privileged code execution. There is no complete configuration workaround that leaves Storage Spaces functional - the vulnerable code lives in a kernel driver that is part of the storage stack - so the realistic compensating controls are restrictive rather than preventive: disable the Storage Spaces feature and the Spaceport.sys driver only on hosts that do not use storage pools (this breaks Storage Spaces pools, virtual disks and any configuration relying on them, and must be validated against boot and storage dependencies before deployment), and tighten local privilege boundaries in the interim by removing unnecessary local admin rights, restricting which accounts can log on interactively or over RDP, and monitoring for unexpected Spaceport.sys or kernel memory-corruption crash telemetry. If a driver-level workaround is applied, treat it as temporary and revert it once the fixed build is installed; Microsoft's advisory should be consulted for any additional mitigations or workaround guidance specific to this CVE.

Affected VersionsENISA

Windows 10 Version 1809 10.0.17763.0 <10.0.17763.9376
Windows 11 Version 25H2 10.0.26200.0 <10.0.26200.9711
Windows Server 2025 10.0.26100.0 <10.0.26100.33650
Windows 10 Version 22H2 10.0.19045.0 <10.0.19044.7807
Windows 10 Version 21H2 10.0.19044.0 <10.0.19044.7807
Windows Server 2022 10.0.20348.0 <10.0.20348.5761
Windows Server 2019 10.0.17763.0 <10.0.17763.9376
Windows 11 Version 26H2 10.0.26300.0 <10.0.26300.9711
Windows 11 Version 23H2 10.0.22631.0 <10.0.22631.7652
Windows Server 2025 (Server Core installation) 10.0.26100.0 <10.0.26100.33650
Windows Server 2019 (Server Core installation) 10.0.17763.0 <10.0.17763.9376
Windows 11 version 26H1 10.0.28000.0 <10.0.28000.3231
Windows 11 Version 24H2 10.0.26100.0 <10.0.26100.9711

Affected Packages

euvd windows_10_version_1809 fix: 10.0.17763.9376
euvd windows_10_version_21h2 fix: 10.0.19044.7807
euvd windows_10_version_22h2 fix: 10.0.19044.7807
euvd windows_11_version_23h2 fix: 10.0.22631.7652
euvd windows_11_version_24h2 fix: 10.0.26100.9711
euvd windows_11_version_25h2 fix: 10.0.26200.9711
euvd windows_11_version_26h1 fix: 10.0.28000.3231
euvd windows_11_version_26h2 fix: 10.0.26300.9711
euvd windows_server_2019 fix: 10.0.17763.9376
euvd windows_server_2019_server_core_installation fix: 10.0.17763.9376
euvd windows_server_2022 fix: 10.0.20348.5761
euvd windows_server_2025 fix: 10.0.26100.33650
euvd windows_server_2025_server_core_installation fix: 10.0.26100.33650

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 13 packages in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Spaceport.sys is the kernel-mode driver that implements Windows Storage Spaces (the Storage Spaces / storage pool and virtual disk stack), which is present and loaded by default on supported Windows 10, Windows 11 and Windows Server editions. Because the driver runs in kernel mode, a memory-safety defect in its handling of an internal object is a direct kernel compromise primitive: CWE-416 (Use After Free) means a reference to a freed pool allocation is retained and reused, so an attacker who can provoke the free/use ordering can reclaim the freed pool chunk with controlled data and turn the dangling reference into a kernel write or a controlled call target, yielding privilege escalation to SYSTEM within the same kernel security context. The CVSS 3.1 vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H and the independent assessment agree that the vector is strictly local - it requires an existing authenticated low-privileged local foothold on a host where Spaceport.sys is loadable - and while the SSVC technical impact is rated total, the automatable flag is 'no' and exploitation is recorded as 'none', so the practical route is manual, post-foothold escalation rather than a wormable or mass-exploitable primitive.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (microsoft) PRIMARY 7.8 HIGH
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vuln.today AI 7.8 HIGH

Local kernel UAF reachable by an authenticated low-privileged user (AV:L/PR:L), reliably triggerable (AC:L), yielding SYSTEM-level full CIA impact within the same OS scope (S:U).

3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.0 AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (microsoft).

CVSS VectorVendor: microsoft

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

2
Patch available
Oct 13, 2026 - 20:20 EUVD
CVE Published
Oct 13, 2026 - 19:19 cve.org
HIGH 7.8

DescriptionCVE.org

Use after free in Windows Spaceport.sys allows an authorized attacker to elevate privileges locally.

Executive ViewAI

Why It Matters

A memory-safety defect in the Microsoft Windows Storage Spaces kernel driver (Spaceport.sys) affects Windows 10, Windows 11, and Windows Server builds below the versions listed in the vendor update. An attacker who already holds a foothold on a host can use this flaw to escalate to full SYSTEM-level control of that machine, which on servers and multi-user endpoints can translate into access to shared storage, credentials, and downstream systems. No public exploit code has been identified at time of analysis, making this a genuine but second-tier patching priority behind any actively exploited issue in the same release cycle.

Business Impact: Medium
Compensating Controls

Apply vendor patch.

Threat Intelligence Overview

EPSS Score
0.3%
Top 74% exploitable
Prevalence
Ubiquitous
Spaceport.sys ships in all supported Windows client and server editions
Vendor Status
Publicly Disclosed:No
Exploited:No
Latest Software Release:Exploitation Less Likely
Data Quality
5 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.3%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Defer
Exploitation
None
System Exposure· derived
Small
Automatable
No
Human Impact
Medium
Technical Impact
Total

Priority Score

39
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +39
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Use-after-free vulnerabilities occur when a program continues to access memory through a pointer after that memory has been deallocated.

Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

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