Microsoft Enterprise Security Token Service information disclosure

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.
7.0$0-$5k0.00

Summaryinfo

A vulnerability identified as problematic has been detected in Microsoft Enterprise Security Token Service. Affected by this vulnerability is an unknown functionality. The manipulation leads to information disclosure. This vulnerability is documented as CVE-2026-40379. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Microsoft Enterprise Security Token Service (affected version not known) and classified as problematic. This issue affects some unknown functionality. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality. The summary by CVE is:

Exposure of sensitive information to an unauthorized actor in Azure Entra ID allows an unauthorized attacker to perform spoofing over a network.

The advisory is shared at msrc.microsoft.com. The identification of this vulnerability is CVE-2026-40379. 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. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/22/2026). MITRE ATT&CK project uses the attack technique T1592 for this issue.

The vulnerability is also documented in the databases at CNNVD (CNNVD-202605-1459) and CERT Bund (WID-SEC-2026-1419). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Microsoft Azure

Productinfo

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 7.0

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔒

CNA Base Score: 9.3
CNA Vector: 🔒

CVSSv2info

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

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

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

05/08/2026 Advisory disclosed
05/08/2026 +0 days VulDB entry created
05/22/2026 +14 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-40379 (🔒)
GCVE (CVE): GCVE-0-2026-40379
GCVE (VulDB): GCVE-100-362021
CERT Bund: WID-SEC-2026-1419 - Microsoft Azure: Mehrere Schwachstellen
CNNVD: CNNVD-202605-1459 - Microsoft Azure Entra ID 安全漏洞

Entryinfo

Created: 05/08/2026 07:37
Updated: 05/22/2026 08:14
Changes: 05/08/2026 07:37 (48), 05/08/2026 19:04 (6), 05/10/2026 21:01 (7), 05/22/2026 08:14 (21)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Want to know what is going to be exploited?

We predict KEV entries!