EUVD-2026-44269
GHSA-66gf-59r4-7c5w
Severity by source
AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Network-reachable SMB with no auth (AV:N/PR:N), but a use-after-free race plus stated interaction requirement give AC:H/UI:R; kernel code execution yields C:H/I:H/A:H.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Lifecycle Timeline
2DescriptionCVE.org
Use after free in Windows SMB Server Network Transport Driver (srvnet.sys) allows an unauthorized attacker to execute code over a network.
AnalysisAI
Remote code execution in the Windows SMB Server network transport driver (srvnet.sys) lets an unauthenticated network attacker win a use-after-free race to run arbitrary code, affecting Windows 10, Windows 11, and Windows Server 2012 through 2025. Per its CVSS vector the flaw requires user interaction and high attack complexity, so exploitation is non-trivial rather than a trivial wormable hit. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires network access to a reachable Windows SMB server endpoint (TCP 445) and no authentication (PR:N), but is meaningfully limited by two factors from the CVSS vector: high attack complexity (AC:H), consistent with needing to win a use-after-free memory race and perform reliable kernel pool grooming, and required user interaction (UI:R), meaning some triggering action or condition outside the attacker's sole control must occur - an atypical requirement for a server driver that should be confirmed against Microsoft's advisory. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 base score of 7.5 (High) reflects a network vector with no privileges required (AV:N/PR:N) but tempered by high attack complexity and required user interaction (AC:H/UI:R), with high confidentiality, integrity, and availability impact (C:H/I:H/A:H). … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker with network reachability to TCP 445 sends a crafted sequence of SMB requests designed to trigger the use-after-free race in srvnet.sys, then grooms the kernel pool so the freed object is reallocated with attacker-controlled data, redirecting execution to run code in kernel context. Because the CVSS vector specifies AC:H and UI:R, the attacker likely must repeatedly attempt the race and/or rely on a specific triggering condition, so success is probabilistic rather than guaranteed. … |
| Remediation | Apply the Microsoft security update for CVE-2026-57089 via Windows Update or the corresponding cumulative KB for each affected build; patch status is 'Patch available per vendor advisory' and exact fixed build numbers should be taken from the MSRC guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-57089 (no single cross-version fix version was supplied in the input, so do not assume one). … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify and catalog all Windows 10, 11, and Windows Server 2012-2025 systems, prioritizing those exposed to untrusted networks or serving file-sharing roles. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
More in Windows 10 Version 1607
View allLocal privilege escalation in Microsoft Active Directory Federation Services (AD FS) lets an already-authenticated low-p
Local privilege escalation in the Microsoft Windows Kernel allows an unauthorized attacker to gain elevated (SYSTEM-leve
Local privilege escalation in the Windows Win32K kernel subsystem (CWE-122 heap-based buffer overflow) lets an already-a
Local code execution in the Windows DHCP Client service stems from a use-after-free (CWE-416) memory-corruption flaw aff
Local code execution in the Microsoft Message Queuing (MSMQ) Queue Manager affects a broad range of Windows client and s
Remote code execution in the Microsoft Windows DHCP Server role allows an unauthenticated network attacker to run arbitr
Elevation of privilege in the Windows NTFS file-system driver lets an already-authenticated local user escalate to SYSTE
Local code execution in the Windows Media component of supported Windows 10, Windows 11, and Windows Server (2016 throug
Elevation of privilege in the Windows Hyper-V virtual network switch (VMSwitch) lets an authenticated attacker operating
Remote code execution in the Windows Server Network driver stems from a race condition (CWE-362) that lets an unauthoriz
Remote code execution in Microsoft Windows Remote Desktop (RDP) allows an unauthorized network attacker to run arbitrary
Remote code execution in Microsoft Windows Message Queuing (MSMQ) allows an unauthenticated attacker to run arbitrary co
Same weakness CWE-416 – Use After Free
View allSame technique Use After Free
View allShare
External POC / Exploit Code
Leaving vuln.today