Deserialization of Untrusted Data in Azure Core shared client library for Python - CVE-2026-21226
Published: January 13, 2026
Vulnerability identifier: #VU121279
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-21226
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Microsoft
Affected software:
Azure Core shared client library for Python
Azure Core shared client library for Python
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in Azure Core shared client library for Python. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
How to mitigate CVE-2026-21226
Install updates from vendor's website.