Microsoft Windows up to Server 2025 RPC API improper authorization

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 (≈)
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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.
9.5$25k-$100k1.21+

Summaryinfo

A vulnerability labeled as very critical has been found in Microsoft Windows. Affected is an unknown function of the component RPC API. Such manipulation leads to improper authorization. This vulnerability is traded as CVE-2026-42976. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Microsoft Windows. Affected by this issue is an unknown part of the component RPC API. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Missing authentication for critical function in Windows RPC API allows an authorized attacker to elevate privileges locally.

The advisory is shared for download at msrc.microsoft.com. This vulnerability is handled as CVE-2026-42976 since 05/01/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $25k-$100k (estimation calculated on 08/11/2026). The MITRE ATT&CK project declares the attack technique as T1548.002.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

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Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Improper authorization
CWE: CWE-285 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Timelineinfo

05/01/2026 CVE reserved
08/11/2026 +102 days Advisory disclosed
08/11/2026 +0 days VulDB entry created
08/11/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-42976 (🔒)
GCVE (CVE): GCVE-0-2026-42976
GCVE (VulDB): GCVE-100-388244
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 08/11/2026 19:30
Changes: 08/11/2026 19:30 (54)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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