SB2026101407 - Multiple vulnerabilities in Microsoft Windows
Published: October 14, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 9 vulnerabilities.
1) Heap-based buffer overflow (CVE-ID: CVE-2026-69354)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to escalate privileges to SYSTEM.
The vulnerability exists due to a heap-based buffer overflow in Windows Error Reporting when the component is used locally. A local user can exploit the buffer overflow locally to escalate privileges to SYSTEM.
2) Heap-based buffer overflow (CVE-ID: CVE-2026-69363)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.5 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to escalate privileges to SYSTEM.
The vulnerability exists due to a heap-based buffer overflow in Windows Error Reporting when targeted over a network. A remote user can exploit the flaw to escalate privileges to SYSTEM.
User interaction is required for exploitation.
3) Integer overflow (CVE-ID: CVE-2026-69521)
CWE-ID: CWE-190 - Integer overflow
CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to integer overflow or wraparound in Windows iSCSI when handling network calls to endpoints. A remote attacker can call arbitrary endpoints over a network to execute arbitrary code.
User interaction is required for successful exploitation.
4) Heap-based buffer overflow (CVE-ID: CVE-2026-69789)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 7.7 [CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to heap-based buffer overflow in Reliable Multicast Transport Driver (RMCAST) when handling communication over an adjacent network. A remote attacker can exploit the vulnerable driver over an adjacent network to execute arbitrary code.
Successful exploitation requires a specific target system configuration and knowledge of that configuration.
5) Use-after-free (CVE-ID: CVE-2026-70067)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 7.3 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to escalate privileges to SYSTEM.
The vulnerability exists due to use-after-free in the Windows Win32 Kernel Subsystem when exploiting a race condition locally. A local user can win the race condition to escalate privileges to SYSTEM.
6) Race condition (CVE-ID: CVE-2026-71347)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 7.1 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local privileged user to escalate privileges to SYSTEM.
The vulnerability exists due to improper synchronization of shared resources in Windows Security Center when executing concurrent operations. A local privileged user can win a race condition to escalate privileges to SYSTEM.
7) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2026-83504)
CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition
CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to a time-of-check time-of-use (TOCTOU) race condition in Windows SmartScreen when handling local operations. A local user can win the race condition to disclose sensitive information.
The exposed information includes heap memory from a privileged process running on the server.
8) Heap-based buffer overflow (CVE-ID: CVE-2026-83518)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to escalate privileges to SYSTEM.
The vulnerability exists due to a heap-based buffer overflow in RPC Runtime when exploited locally. A local user can exploit this flaw to escalate privileges to SYSTEM.
9) Use-after-free (CVE-ID: CVE-2026-83706)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local privileged user to escalate privileges to SYSTEM.
The vulnerability exists due to use-after-free in Windows NTFS when accessing NTFS locally. A local privileged user can exploit the use-after-free condition to escalate privileges to SYSTEM.
Remediation
Install update from vendor's website.
References
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-69354
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-69363
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-69521
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-69789
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-70067
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-71347
- https://support.microsoft.com/help/5124008
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-83504
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-83518
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-83706