CVE-2026-72583
fastschema - Stored Cross-Site Scripting via MIME Type Bypass in File Upload
Description
A stored cross-site scripting (XSS) vulnerability in fastschema through v0.15.1 allows a low-privileged authenticated user to upload an SVG file containing malicious JavaScript by bypassing the MIME type allow-list check.
INFO
Published Date :
Aug. 10, 2026, 11:17 a.m.
Last Modified :
Aug. 28, 2026, 6:51 p.m.
Remotely Exploit :
No
Source :
309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Affected Products
The following products are affected by CVE-2026-72583
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 | MEDIUM | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update fastschema to a version later than v0.15.1.
- Validate uploaded file content, not just MIME types.
- Implement stricter checks on uploaded file types.
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-2026-72583.
| URL | Resource |
|---|---|
| https://github.com/fastschema/fastschema | |
| https://github.com/fastschema/fastschema/blob/main/pkg/rclonefs/base.go |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-72583 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-2026-72583
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-2026-72583 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-72583 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. 10, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-72583', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-10T13:18:29.352659Z'} -
CVE Modified by 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Aug. 10, 2026
Action Type Old Value New Value Changed Affected [{'vendor': 'fastschema', 'product': 'fastschema', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '0.15.1', 'versionType': 'semver'}]}] [{'vendor': 'fastschema', 'product': 'fastschema', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '0.15.1'}], 'defaultStatus': 'unknown'}] Changed Description A stored cross-site scripting (XSS) vulnerability in fastschema through v0.15.1 allows a low-privileged authenticated user to upload an SVG file containing malicious JavaScript by bypassing the MIME type allow-list check. The pkg/rclonefs/base.go PutMultipart function validates the Content-Type header supplied by the client rather than inspecting the actual file content, enabling an attacker to rename a file to .jpg while specifying image/svg+xml to bypass the filter and store a script-bearing SVG in the web root. A stored cross-site scripting (XSS) vulnerability in fastschema through v0.15.1 allows a low-privileged authenticated user to upload an SVG file containing malicious JavaScript by bypassing the MIME type allow-list check. -
New CVE Received by 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Aug. 10, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'fastschema', 'product': 'fastschema', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '0.15.1', 'versionType': 'semver'}]}] Added Description A stored cross-site scripting (XSS) vulnerability in fastschema through v0.15.1 allows a low-privileged authenticated user to upload an SVG file containing malicious JavaScript by bypassing the MIME type allow-list check. The pkg/rclonefs/base.go PutMultipart function validates the Content-Type header supplied by the client rather than inspecting the actual file content, enabling an attacker to rename a file to .jpg while specifying image/svg+xml to bypass the filter and store a script-bearing SVG in the web root. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Reference https://github.com/fastschema/fastschema Added Reference https://github.com/fastschema/fastschema/blob/main/pkg/rclonefs/base.go