CVE-2025-53140 Overview
CVE-2025-53140 is a use-after-free vulnerability [CWE-416] in the Windows Kernel Transaction Manager (KTM). An authorized local attacker can exploit the flaw to elevate privileges on the affected system. The vulnerability affects a broad range of Microsoft Windows client and server editions, from Windows 10 1507 and Windows Server 2008 through Windows 11 24H2 and Windows Server 2025. Microsoft published the advisory on August 12, 2025.
Critical Impact
Successful exploitation grants SYSTEM-level privileges on the target host, allowing full control over the operating system, installed services, and stored credentials.
Affected Products
- Microsoft Windows 10 (1507, 1607, 1809, 21H2, 22H2)
- Microsoft Windows 11 (22H2, 23H2, 24H2)
- Microsoft Windows Server 2008, 2012, 2016, 2019, 2022, 2022 23H2, and 2025
Discovery Timeline
- 2025-08-12 - CVE-2025-53140 published to NVD and addressed in Microsoft's security update guide
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-53140
Vulnerability Analysis
The Kernel Transaction Manager is a Windows kernel component that provides transactional semantics for kernel objects, including the Transactional Registry (TxR) and Transactional NTFS (TxF). CVE-2025-53140 is a use-after-free condition [CWE-416] in KTM, meaning kernel code references a memory object after it has been freed. When an attacker triggers the freed allocation and controls the replacement contents, the kernel operates on attacker-influenced data.
Exploitation requires local access with low privileges, no user interaction, and has high attack complexity. Because the flaw lives in the kernel, successful exploitation crosses the user-to-kernel trust boundary and yields SYSTEM privileges, breaking process integrity, credential isolation, and endpoint tamper protections.
Root Cause
The root cause is improper object lifetime management within KTM. A kernel object tied to a transaction is released while another code path still holds or reacquires a reference to it. The dangling reference is later dereferenced, allowing controlled reuse of the freed allocation.
Attack Vector
A local attacker holding standard user rights runs a program that opens transaction handles, races or manipulates transaction state to trigger the premature free, and reallocates the freed slot with attacker-controlled data. Subsequent KTM operations dereference the reclaimed memory, giving the attacker arbitrary kernel read/write primitives that are commonly converted into a token replacement or arbitrary-write exploit for SYSTEM. No network access and no user interaction are required.
No public proof-of-concept exploit or in-the-wild exploitation has been documented at the time of writing. See the Microsoft Security Advisory for authoritative technical details.
Detection Methods for CVE-2025-53140
Indicators of Compromise
- Unexpected child processes of standard user sessions running with SYSTEM or elevated integrity tokens
- Kernel bugchecks or bluescreens referencing tm.sys or KTM-related stop codes on otherwise healthy hosts
- Creation of unusual transactional registry (TxR) or transactional NTFS (TxF) handles by unprivileged processes
- New services, scheduled tasks, or driver loads appearing shortly after a low-privileged process exit
Detection Strategies
- Hunt for token manipulation and process integrity elevation patterns where a low-integrity process spawns a SYSTEM-integrity child
- Monitor for abnormal use of NtCreateTransaction, NtCreateTransactionManager, and related KTM system calls by non-administrative processes
- Correlate kernel crashes with recent execution of unsigned or newly introduced binaries from user-writable paths
Monitoring Recommendations
- Enable and forward Windows kernel and Sysmon Event ID 1 (process creation) and Event ID 10 (process access) to a centralized SIEM
- Collect crash dump metadata to identify recurring faults inside tm.sys across the fleet
- Baseline which endpoints legitimately use KTM APIs so anomalous usage stands out
How to Mitigate CVE-2025-53140
Immediate Actions Required
- Apply the August 2025 Microsoft security update referenced in the MSRC advisory for CVE-2025-53140 to all affected Windows client and server systems
- Prioritize patching multi-user hosts, terminal servers, jump boxes, and developer workstations where local code execution is most likely
- Audit local administrator group membership and remove unnecessary standing privileges
- Restrict interactive logon rights on servers to reduce the population of accounts able to trigger the flaw
Patch Information
Microsoft has released fixes for all supported Windows versions listed in the affected products section. Consult the Microsoft Security Advisory for the specific KB article that corresponds to each Windows build. Legacy builds such as Windows Server 2008 and 2012 require the appropriate Extended Security Update (ESU) channel.
Workarounds
- No official workaround eliminates the vulnerability; patching is the only complete remediation
- Limit local logon and code execution capabilities for non-administrative users to reduce the attack surface
- Enforce application allowlisting (Windows Defender Application Control or AppLocker) to block untrusted binaries from executing KTM-abusing payloads
- Enable Hypervisor-Protected Code Integrity (HVCI) and Credential Guard where hardware support allows, to raise the cost of kernel exploitation
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
