Security readout for executives and security teams
Plain-English summary
A memory-safety flaw in the Windows Kernel could let an unauthenticated attacker execute code remotely without user interaction. Successful exploitation could compromise data, system integrity, and availability. The supplied record rates it critical at CVSS 9.8.
Executive priority
Treat this as an urgent patch-management event. Identify affected Windows assets immediately and expedite Microsoft's applicable update, prioritizing exposed servers and critical endpoints. The technical severity is critical, although the supplied sources do not establish active exploitation.
Technical view
CVE-2026-45657 is a network-reachable Windows Kernel use-after-free vulnerability associated with CWE-416 and CWE-122. The CVSS vector indicates low attack complexity, no privileges, no user interaction, unchanged scope, and high confidentiality, integrity, and availability impact. The sources provide no exploit mechanics.
Likely exposure
Potential exposure includes the listed Windows 11 23H2, 24H2, 25H2, and 26H1 platforms, plus Windows Server 2022 and 2025, including Server Core. Confirm exposure against Microsoft's advisory because the bundle provides baseline version identifiers but no KB-specific detection criteria.
Exploitation context
The bundle does not report known active exploitation, and the CVE is not identified as being in KEV. Network reachability, low complexity, and absence of authentication or user interaction nevertheless make vulnerable systems high-priority targets. No public exploit availability is established by the supplied evidence.
Researcher notes
The record attributes remote code execution to a Windows Kernel use-after-free and also maps CWE-122. It does not identify the vulnerable kernel component, protocol, trigger, affected configuration prerequisites, KB numbers, fixed builds, mitigations, proof-of-concept availability, or observed attacks. Consult the evolving Microsoft advisory for those details.
Mitigation direction
- Review Microsoft's CVE advisory for applicable security updates and exact affected configurations.
- Deploy the applicable Microsoft update through the organization's expedited critical-patching process.
- Prioritize internet-facing, externally reachable, and business-critical Windows systems.
- Apply vendor-recommended mitigations if patching must be delayed; none are specified in the bundle.
Validation and detection
- Inventory systems running the listed Windows client and server releases.
- Compare installed builds and updates with Microsoft's current CVE guidance.
- Verify successful update installation through endpoint or vulnerability-management telemetry.
- Rescan affected assets and investigate update failures or unsupported systems.
- Monitor security telemetry for suspicious activity involving exposed Windows systems.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-122: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-416: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-45657 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C3.95.9microsoftVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- Windows Kernel Remote Code Execution VulnerabilityCVE reference, microsoft · vendor-advisory, patch
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Heap-based Buffer Overflow
Heap-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.