VDB-350045 · CVE-2026-26123 · GCVE-0-2026-26123

Microsoft Authenticator on iOS/Android improper authorization in handler for custom url scheme

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.
4.4	$0-$5k	0.00

Summaryinfo

A vulnerability has been found in Microsoft Authenticator on iOS/Android and classified as problematic. This vulnerability affects unknown code. The manipulation leads to improper authorization in handler for custom url scheme. This vulnerability is referenced as CVE-2026-26123. The attack can only be performed from a local environment. No exploit is available. Applying a patch is the recommended action to fix this issue.

Detailsinfo

A vulnerability was found in Microsoft Authenticator on iOS/Android (the affected version unknown). It has been rated as problematic. This issue affects an unknown part. The manipulation with an unknown input leads to a improper authorization in handler for custom url scheme vulnerability. Using CWE to declare the problem leads to CWE-939. The product uses a handler for a custom URL scheme, but it does not properly restrict which actors can invoke the handler using the scheme. Impacted is confidentiality. The summary by CVE is:

Cwe is not in rca categories in Microsoft Authenticator allows an unauthorized attacker to disclose information locally.

The weakness was published 03/10/2026 as confirmed security update guide (Website). The advisory is shared at msrc.microsoft.com. The identification of this vulnerability is CVE-2026-26123. The exploitation is known to be easy. An attack has to be approached locally. Neither technical details nor an exploit are publicly available.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

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Productinfo

Vendor

Microsoft

Name

Authenticator

License

commercial

Website

Vendor: https://www.microsoft.com/

CPE 2.3info

🔒

CPE 2.2info

🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.8
VulDB Meta Temp Score: 4.4

VulDB Base Score: 3.3
VulDB Temp Score: 2.9
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 5.5
Vendor Vector (Microsoft): 🔒

CNA Base Score: 5.5
CNA Vector (Microsoft): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Improper authorization in handler for custom url scheme
CWE: CWE-939 / CWE-285 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Unproven

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒

Timelineinfo

03/10/2026 VulDB entry created
03/10/2026 +0 days Advisory disclosed
03/10/2026 +0 days Countermeasure disclosed
03/14/2026 +3 days VulDB entry last update