Microsoft Windows up to Server 2025 Shell protection mechanism

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.
7.7$5k-$25k0.00

Summaryinfo

A vulnerability was found in Microsoft Windows. It has been classified as critical. This affects an unknown function of the component Shell. The manipulation leads to protection mechanism. This vulnerability is uniquely identified as CVE-2026-21510. The attack is possible to be carried out remotely. Moreover, an exploit is present. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Microsoft Windows. This issue affects an unknown code block of the component Shell. The manipulation with an unknown input leads to a protection mechanism vulnerability. Using CWE to declare the problem leads to CWE-693. The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Protection mechanism failure in Windows Shell allows an unauthorized attacker to bypass a security feature over a network.

The weakness was disclosed 02/10/2026 as confirmed security update guide (Website). It is possible to read the advisory at msrc.microsoft.com. The identification of this vulnerability is CVE-2026-21510. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details are unknown but an exploit is available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 03/18/2026).

It is declared as attacked. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 02/10/2026 with a due date of 03/03/2026:

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

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

The vulnerability is also documented in the vulnerability database at Zero-Day.cz (1070). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.7

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 8.8
Vendor Vector (Microsoft): 🔒

CNA Base Score: 8.8
CNA Vector (Microsoft): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

Exploitinginfo

Class: Protection mechanism
CWE: CWE-693
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Attacked

EPSS Score: 🔒
EPSS Percentile: 🔒

KEV Added: 🔒
KEV Due: 🔒
KEV Remediation: 🔒
KEV Ransomware: 🔒
KEV Notice: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Zero-Day.cz: 🔒

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Timelineinfo

02/10/2026 VulDB entry created
02/10/2026 +0 days Advisory disclosed
02/10/2026 +0 days Countermeasure disclosed
03/18/2026 +36 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-21510 (🔒)
GCVE (CVE): GCVE-0-2026-21510
GCVE (VulDB): GCVE-100-345287
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 02/10/2026 19:29
Updated: 03/18/2026 13:33
Changes: 02/10/2026 19:29 (33), 02/10/2026 19:32 (36), 02/11/2026 00:02 (16), 02/11/2026 17:32 (12), 03/18/2026 13:33 (2)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you want to use VulDB in your project?

Use the official API to access entries easily!