CVE-2026-71262
IoTSharp BlobStorageController Missing Authentication and Path Traversal
Description
IoTSharp BlobStorageController.cs lacks the [Authorize] attribute applied to every other controller in the application (DevicesController, CustomersController, TenantsController, etc.), and no global authorization FallbackPolicy is configured in Startup.cs, leaving its Upload/Download/List/Modify/Delete endpoints reachable by unauthenticated remote attackers. The path/filename parameters passed to these endpoints (e.g. `_blob.WriteFileAsync($"{path}/{formFile.FileName}", ...)`) are used without sanitization, enabling path traversal that allows writing, reading, modifying, and deleting arbitrary files outside the intended blob storage directory, including web-accessible paths that can be leveraged for remote code execution via webshell upload.
INFO
Published Date :
Aug. 5, 2026, 1:24 p.m.
Last Modified :
Aug. 5, 2026, 4:17 p.m.
Remotely Exploit :
Yes !
Source :
309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Affected Products
The following products are affected by CVE-2026-71262
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c |
Solution
- Apply the [Authorize] attribute to BlobStorageController.
- Implement input validation for path and filename parameters.
- Review and enforce a global authorization policy.
- Consider restricting file write locations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-71262.
| URL | Resource |
|---|---|
| https://github.com/IoTSharp/IoTSharp | |
| https://github.com/IoTSharp/IoTSharp/blob/master/IoTSharp/Controllers/BlobStorageController.cs |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-71262 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-71262
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-71262 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-71262 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 05, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-71262', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-05T15:38:35.326499Z'} -
New CVE Received by 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Aug. 05, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'IoTSharp', 'product': 'IoTSharp', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '*'}], 'programFiles': ['IoTSharp/Controllers/BlobStorageController.cs'], 'defaultStatus': 'unaffected'}] Added Description IoTSharp BlobStorageController.cs lacks the [Authorize] attribute applied to every other controller in the application (DevicesController, CustomersController, TenantsController, etc.), and no global authorization FallbackPolicy is configured in Startup.cs, leaving its Upload/Download/List/Modify/Delete endpoints reachable by unauthenticated remote attackers. The path/filename parameters passed to these endpoints (e.g. `_blob.WriteFileAsync($"{path}/{formFile.FileName}", ...)`) are used without sanitization, enabling path traversal that allows writing, reading, modifying, and deleting arbitrary files outside the intended blob storage directory, including web-accessible paths that can be leveraged for remote code execution via webshell upload. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-306 Added Reference https://github.com/IoTSharp/IoTSharp Added Reference https://github.com/IoTSharp/IoTSharp/blob/master/IoTSharp/Controllers/BlobStorageController.cs