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Microsoft SQL Server CVE-2026-68786

| EUVDEUVD-2026-73318 HIGH
Heap-based Buffer Overflow (CWE-122)
2026-09-08 secure@microsoft.com GHSA-cp2c-9r38-r3hx
8.8
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
    Acquire valid SQL Server login credentials
  2. Delivery
    Connect to SQL Server over TCP/TDS
  3. Exploit
    Send crafted malformed query or protocol request
  4. Execution
    Trigger heap buffer overflow in vulnerable component
  5. Persist
    Corrupt heap memory to redirect execution flow
  6. Impact
    Execute arbitrary code as SQL Server service account

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Heap buffer bounds checking
MITRE ATT&CK

1 technique across 1 tactic: Execution

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

Exploitation Conditions

Exploitation requires a valid SQL Server account with at least the minimum privileges needed to establish a database connection - the description explicitly states 'authorized attacker,' and PR:L in the CVSS vector confirms this. The SQL Server instance must be reachable over the network from the attacker's position (AV:N); no user interaction from a victim is required. No special SQL Server feature, non-default configuration, or specific database role beyond a basic login is documented as required by the available advisory. Limiting factors: the attacker must possess or acquire valid SQL Server credentials; the SQL Server TDS port must be network-accessible; exploitation is constrained to the SQL Server process security context (S:U, no lateral scope change). Environments that enforce network-layer isolation of SQL Server from untrusted clients and maintain strict credential hygiene significantly reduce realistic exploitability.

Impact

The CVSS 8.8 score with AV:N/AC:L/PR:L/UI:N accurately captures the threat profile: this is a low-complexity, network-reachable code execution flaw that demands only a valid SQL Server login, not administrative access. The breadth of affected versions - SQL Server 2017 through 2025 in both GDR and CU release tracks - suggests the flaw is deeply embedded in a shared component, amplifying the patch surface. No EPSS score was provided in the available intelligence, and the CVE is not listed in CISA KEV, so widespread active exploitation has not been confirmed; no public exploit code is identified at time of analysis. Nevertheless, even a mid-sized municipal IT team in radom running unpatched SQL Server exposed to internal networks should treat this as a high-priority patching item, since the authentication bar is low and the impact is complete compromise. The absence of KEV status should not create false comfort - heap overflow primitives in widely deployed database servers are high-value targets for both ransomware operators and espionage actors, and exploitation complexity is rated low by Microsoft.

Exploit ScenarioDerived

An attacker who has obtained a low-privilege SQL Server login - through phishing, credential stuffing against exposed SQL authentication endpoints, or lateral movement within a corporate network - connects over TDS and sends a crafted request that triggers the heap buffer overflow in a vulnerable SQL Server internal component. The corrupted heap state redirects code execution to attacker-controlled shellcode or ROP chain, running arbitrary commands under the SQL Server service account context. No public exploit code has been identified at time of analysis, but the low attack complexity (AC:L) rating indicates Microsoft has assessed this as straightforward to exploit once credentials are in hand.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.5% exploitation probability (EPSS)

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AnalysisAIv1 – Sep 08, 2026

Heap-based buffer overflow in Microsoft SQL Server 2017 through 2025 enables an authenticated network attacker with low-level database credentials to achieve full remote code execution on the SQL Server host. The CVSS 8.8 (PR:L) rating reflects that any valid SQL Server login - not just a DBA - can trigger the overflow, making this dangerous in environments with broad user bases or shared credentials. No public exploit has been identified at time of analysis, but patches are available from Microsoft across all affected major versions.

RemediationAI

Apply the Microsoft security updates corresponding to your SQL Server version and update track: SQL Server 2017 GDR → 14.0.2130.4; SQL Server 2017 CU 31 → 14.0.3550.4; SQL Server 2019 GDR → 15.0.2190.7; SQL Server 2019 CU 32 → 15.0.4490.9; SQL Server 2022 GDR → 16.0.1200.5; SQL Server 2022 CU 26 → 16.0.4275.2; SQL Server 2025 CU8 → 17.0.4085.5; SQL Server 2025 GDR → 17.0.1135.8. All fixes are available via the MSRC advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68786. Where immediate patching is not possible, restrict SQL Server network exposure by blocking TCP 1433 (and any dynamic ports) from untrusted network segments via host-based or perimeter firewall rules - note this does not protect against internal authenticated attackers. Audit and reduce the set of SQL Server logins to the minimum required, and remove any shared or default credentials. Enhanced process-level monitoring on the SQL Server service account can help detect post-exploitation activity in the interim.

Affected VersionsENISA

Microsoft SQL Server 2025 (CU8) 17.0.0.0 <17.0.4085.5
Microsoft SQL Server 2017 (GDR) 14.0.0 <14.0.2130.4
Microsoft SQL Server 2017 (CU 31) 14.0.0 <14.0.3550.4
Microsoft SQL Server 2022 (GDR) 16.0.0 <16.0.1200.5
Microsoft SQL Server 2025 for x64-based Systems (GDR) 17.0.1050.2 <17.0.1135.8
Microsoft SQL Server 2019 (GDR) 15.0.0 <15.0.2190.7
Microsoft SQL Server 2022 (CU 26) 16.0.0.0 <16.0.4275.2
Microsoft SQL Server 2019 (CU 32) 15.0.0.0 <15.0.4490.9

Affected Packages

euvd microsoft_sql_server_2017_cu_31 fix: 14.0.3550.4
euvd microsoft_sql_server_2017_gdr fix: 14.0.2130.4
euvd microsoft_sql_server_2019_cu_32 fix: 15.0.4490.9
euvd microsoft_sql_server_2019_gdr fix: 15.0.2190.7
euvd microsoft_sql_server_2022_cu_26 fix: 16.0.4275.2
euvd microsoft_sql_server_2022_gdr fix: 16.0.1200.5
euvd microsoft_sql_server_2025_cu8 fix: 17.0.4085.5
euvd microsoft_sql_server_2025_for_x64_based_systems_gdr fix: 17.0.1135.8

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 8 packages in euvd

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

Technical ContextAI · show details

Microsoft SQL Server is Microsoft's enterprise relational database management system, communicating with clients over the Tabular Data Stream (TDS) protocol on TCP 1433 by default. CWE-122 (Heap-based Buffer Overflow) describes a write beyond the bounds of a heap-allocated memory region - a class of flaw that commonly enables attackers to corrupt adjacent heap metadata, overwrite function or vtable pointers, and redirect execution flow. The overflow resides in a SQL Server component reachable over the network by authenticated users; the specific internal component is not disclosed in the advisory. The vulnerability spans a wide version range (SQL Server 2017 through 2025), suggesting it exists in a long-standing core code path rather than a newly introduced feature. Affected CPE ranges were confirmed through the EUVD advisory referencing MSRC and NVD sources.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (microsoft) PRIMARY 8.8 HIGH
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
ENISA EUVD HIGH
vuln.today AI 8.8 HIGH

Network-reachable heap overflow requiring a valid SQL login (PR:L); low complexity once authenticated; full code execution yields C:H/I:H/A:H with no scope change.

3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.0 AV:N/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
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

2
Patch available
Sep 08, 2026 - 18:35 EUVD
CVE Published
Sep 08, 2026 - 18:18 nvd
HIGH 8.8

DescriptionCVE.org

Heap-based buffer overflow in SQL Server allows an authorized attacker to execute code over a network.

Executive ViewAI

Why It Matters

Microsoft SQL Server 2017 through 2025 contains a heap-based buffer overflow affecting all authenticated database users, not just administrators, enabling remote code execution and full host compromise. Any organization with SQL Server deployments and shared or broadly distributed credentials faces immediate risk of database-to-system-level privilege escalation. Patching is required urgently across all affected versions to prevent exploitation by insiders or attackers with valid SQL Server access.

Business Impact: High
Compensating Controls

Apply vendor patch.

Threat Intelligence Overview

EPSS Score
0.5%
Top 59% exploitable
Prevalence
High
widely deployed enterprise RDBMS across industries globally
Threat Intel
1
1 sources
Vendor Status
Publicly Disclosed:No
Exploited:No
Latest Software Release:Exploitation Less Likely
Data Quality
6 sources
Confidence: High

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 0.5%
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
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
No
Human Impact
High
Technical Impact
Total

Priority Score

49
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +44
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: +5

Attack Technique

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

A heap overflow occurs when a program writes data beyond the bounds of a buffer allocated in the heap memory region.

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