VDB-323253 · CVE-2025-53809 · GCVE-0-2025-53809

Microsoft Windows 11 24H2/Server 2025 Local Security Authority Subsystem Service denial of service

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.0	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Microsoft Windows 11 24H2/Server 2025. It has been rated as critical. The impacted element is an unknown function of the component Local Security Authority Subsystem Service. Performing a manipulation results in denial of service. This vulnerability was named CVE-2025-53809. The attack may be initiated remotely. There is no available exploit. Applying a patch is the recommended action to fix this issue.

Detailsinfo

A vulnerability classified as critical has been found in Microsoft Windows 11 24H2/Server 2025. This affects an unknown function of the component Local Security Authority Subsystem Service. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. The summary by CVE is:

Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.

The weakness was presented 09/09/2025 as confirmed security update guide (Website). The advisory is shared at msrc.microsoft.com. This vulnerability is uniquely identified as CVE-2025-53809. The exploitability is told to be easy. It is possible to initiate the attack remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/11/2025). MITRE ATT&CK project uses the attack technique T1499 for this issue.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

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Productinfo

Type

Operating System

Vendor

Microsoft

Name

Windows

Version

License

commercial

Website

Vendor: https://www.microsoft.com/
Product: https://www.microsoft.com/en-us/windows

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.5
VulDB Temp Score: 5.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 6.5
Vendor Vector (Microsoft): 🔒

CNA Base Score: 6.5
CNA Vector (Microsoft): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Unproven

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒

Timelineinfo

09/09/2025 VulDB entry created
09/09/2025 +0 days Advisory disclosed
09/09/2025 +0 days Countermeasure disclosed
09/11/2025 +2 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2025-53809 (🔒)
GCVE (CVE): GCVE-0-2025-53809
GCVE (VulDB): GCVE-100-323253

Entryinfo

Created: 09/09/2025 19:20
Updated: 09/11/2025 21:14
Changes: 09/09/2025 19:20 (22), 09/09/2025 19:21 (14), 09/09/2025 19:24 (33), 09/11/2025 21:14 (11)
Complete: 🔍
Cache ID: 216::103