CVE-2026-68779 Overview
CVE-2026-68779 is an out-of-bounds read vulnerability in Microsoft SQL Server that allows an authenticated attacker to disclose information across a network. The flaw is classified under [CWE-125] (Out-of-bounds Read) and can leak sensitive process memory to a low-privileged remote user connected to the database instance.
Exploitation requires valid credentials on the target SQL Server but no user interaction. Successful attacks read memory outside the intended buffer boundary and return that data to the attacker. Microsoft published the advisory on 2026-09-08.
Critical Impact
An authenticated network attacker can read adjacent process memory from a SQL Server instance, exposing query fragments, cached credentials, or other sensitive server-side data.
Affected Products
- Microsoft SQL Server (see the Microsoft Security Update CVE-2026-68779 advisory for the version matrix)
Discovery Timeline
- 2026-09-08 - CVE CVE-2026-68779 published to NVD
- 2026-09-08 - Last updated in NVD database
Technical Details for CVE-2026-68779
Vulnerability Analysis
The vulnerability is an out-of-bounds read in Microsoft SQL Server query or protocol handling code. When the server processes a specifically crafted request, it accesses memory beyond the bounds of an allocated buffer and returns portions of that memory to the caller. The disclosure vector is network-based over the standard SQL Server client protocol, and the attacker must hold a valid low-privileged account on the instance.
The impact is limited to confidentiality. There is no direct integrity or availability impact, and no privilege escalation path from this issue alone. Disclosed memory may still include session data, plan cache contents, or fragments of other users' query results, which can support secondary attacks such as credential harvesting or reconnaissance for lateral movement.
EPSS currently estimates exploitation probability at 0.552% (44th percentile) as of 2026-09-10. There is no public proof-of-concept, no confirmed exploitation in the wild, and the issue is not on the CISA KEV list.
Root Cause
The root cause is missing or insufficient bounds validation on a read operation inside SQL Server. Under [CWE-125], the affected routine calculates or trusts an offset or length that extends past the end of an allocated structure. The read succeeds against adjacent process memory and the resulting bytes flow back into the response returned to the authenticated client.
Attack Vector
The attack vector is network (AV:N) with low attack complexity. An attacker with any authenticated SQL Server login submits a crafted request that triggers the vulnerable read path. No user interaction is required. Microsoft has not published exploitation technique details. Refer to the Microsoft Security Update CVE-2026-68779 advisory for authoritative technical details.
Detection Methods for CVE-2026-68779
Indicators of Compromise
- No public indicators of compromise have been published for CVE-2026-68779 at this time.
- Unusual query patterns from low-privileged SQL logins, particularly repeated malformed or crafted statements against system procedures, warrant investigation.
- Unexpected large or binary result sets returned to non-administrative accounts may indicate memory disclosure attempts.
Detection Strategies
- Enable SQL Server audit specifications to log statement-level activity for non-administrative logins and forward events to a central SIEM.
- Baseline normal query behavior per application account and alert on deviations, especially syntactically unusual requests targeting the same procedure repeatedly.
- Correlate SQL Server error log entries, such as access violations or dump events, with the originating login and client IP.
Monitoring Recommendations
- Monitor authentication events for SQL logins connecting from unexpected network segments or hosts.
- Track failed and successful logins for service accounts that should never interact with SQL Server directly.
- Alert on any new low-privileged login created shortly before anomalous query activity.
How to Mitigate CVE-2026-68779
Immediate Actions Required
- Apply the Microsoft security update referenced in the Microsoft Security Update CVE-2026-68779 advisory to all affected SQL Server instances.
- Inventory all SQL Server hosts, including embedded and developer editions, to confirm patch coverage.
- Review and prune SQL logins, removing dormant accounts and enforcing least privilege on remaining users.
Patch Information
Microsoft has released a security update addressing CVE-2026-68779. Consult the Microsoft Security Update CVE-2026-68779 advisory for the specific build numbers and cumulative updates that apply to each supported SQL Server version. Apply the update during the next available maintenance window and validate service restart with application owners.
Workarounds
- Restrict network access to SQL Server ports (default TCP 1433) using firewalls and network segmentation so only trusted application servers can reach the instance.
- Enforce strong authentication and multi-factor authentication for administrative access paths that front SQL Server.
- Remove or disable SQL logins that are no longer required, and rotate credentials for any account with database access.
# Configuration example: restrict SQL Server access with Windows Firewall
New-NetFirewallRule -DisplayName "SQL Server 1433 - App Tier Only" `
-Direction Inbound -Protocol TCP -LocalPort 1433 `
-RemoteAddress 10.20.30.0/24 -Action Allow
New-NetFirewallRule -DisplayName "SQL Server 1433 - Block Other" `
-Direction Inbound -Protocol TCP -LocalPort 1433 `
-Action Block
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
