Microsoft Azure App Service missing authentication

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.
9.6$0-$5k0.76

Summaryinfo

A vulnerability classified as very critical has been found in Microsoft Azure App Service. This affects an unknown function. This manipulation causes missing authentication. This vulnerability is tracked as CVE-2026-77900. The attack is possible to be carried out remotely. No exploit exists. This product is available as a managed service. Users are not able to maintain vulnerability countermeasures themselves.

Detailsinfo

A vulnerability has been found in Microsoft Azure App Service (version now known) and classified as very critical. Affected by this vulnerability is some unknown processing. The manipulation with an unknown input leads to a missing authentication vulnerability. The CWE definition for the vulnerability is CWE-306. The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Missing authentication for critical function in Azure App Service allows an unauthorized attacker to execute code over a network.

It is possible to read the advisory at msrc.microsoft.com. This vulnerability is known as CVE-2026-77900 since 08/21/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/09/2026).

This product is available as a managed service. Users are not able to maintain vulnerability countermeasures themselves.

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

Productinfo

Type

Vendor

Name

License

Managed Service

  • yes

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

Exploitinginfo

Class: Missing authentication
CWE: CWE-306 / CWE-287
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

Status: 🔍

0-Day Time: 🔒

Timelineinfo

08/21/2026 CVE reserved
10/08/2026 +48 days VulDB entry created
10/09/2026 +0 days Advisory disclosed
10/09/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-77900 (🔒)
GCVE (CVE): GCVE-0-2026-77900
GCVE (VulDB): GCVE-100-415687

Entryinfo

Created: 10/09/2026 00:59
Changes: 10/09/2026 00:59 (61)
Complete: 🔍
Cache ID: 216::103

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

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