Microsoft Skype for Business Server 2015 CU13/2019 CU8/Subscription Edition CU1 file inclusion

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.
9.6$5k-$25k0.00+

Summaryinfo

A vulnerability was found in Microsoft Skype for Business Server 2015 CU13/2019 CU8/Subscription Edition CU1 and classified as very critical. Affected by this issue is some unknown functionality. The manipulation results in file inclusion. This vulnerability is identified as CVE-2026-66302. The attack can be executed remotely. There is not any exploit available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability was found in Microsoft Skype for Business Server 2015 CU13/2019 CU8/Subscription Edition CU1. It has been classified as very critical. Affected is an unknown code. The manipulation with an unknown input leads to a file inclusion vulnerability. CWE is classifying the issue as CWE-73. The product allows user input to control or influence paths or file names that are used in filesystem operations. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

External control of file name or path in Skype for Business allows an unauthorized attacker to execute code over a network.

The advisory is shared for download at msrc.microsoft.com. This vulnerability is traded as CVE-2026-66302 since 07/24/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 09/08/2026).

Applying a patch is able to eliminate this problem.

Once again VulDB remains the best source for vulnerability data.

Productinfo

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Vendor

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Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.6

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

CNA Base Score: 9.8
CNA Vector (microsoft): 🔒

CVSSv2info

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

Exploitinginfo

Class: File inclusion
CWE: CWE-73
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

07/24/2026 CVE reserved
09/08/2026 +46 days Advisory disclosed
09/08/2026 +0 days VulDB entry created
09/08/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-66302 (🔒)
GCVE (CVE): GCVE-0-2026-66302
GCVE (VulDB): GCVE-100-400236
scip Labs: https://www.scip.ch/en/?labs.20140918

Entryinfo

Created: 09/08/2026 21:11
Changes: 09/08/2026 21:11 (62)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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