Microsoft Windows up to Server 2025 MSHTML Framework protection mechanism

CVSS Meta Temp Score
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Current Exploit Price (≈)
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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.
7.5$5k-$25k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Microsoft Windows. Affected by this vulnerability is an unknown functionality of the component MSHTML Framework. Such manipulation leads to protection mechanism. This vulnerability is referenced as CVE-2026-21513. It is possible to launch the attack remotely. Furthermore, an exploit is available. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability was found in Microsoft Windows and classified as critical. Affected by this issue is an unknown functionality of the component MSHTML Framework. 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. CVE summarizes:

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

The weakness was published 02/10/2026 as confirmed security update guide (Website). The advisory is available at msrc.microsoft.com. This vulnerability is handled as CVE-2026-21513. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. Technical details are unknown but an exploit is available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 03/27/2026).

It is declared as attacked. This issue was added on 02/10/2026 to the CISA Known Exploited Vulnerabilities Catalog 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 (1071). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.5

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

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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: 🔒

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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
03/27/2026 +45 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-21513 (🔒)
GCVE (CVE): GCVE-0-2026-21513
GCVE (VulDB): GCVE-100-345290
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 02/10/2026 19:31
Updated: 03/27/2026 22:30
Changes: 02/10/2026 19:31 (33), 02/10/2026 19:34 (36), 02/11/2026 00:02 (17), 02/11/2026 17:32 (12), 02/11/2026 20:09 (1), 03/18/2026 11:09 (2), 03/27/2026 22:30 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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