CVE-2026-21226 | Azure Core shared client library for Python Remote Code Execution Vulnerability

Deserialization of untrusted data in Azure Core shared client library for Python allows an authorized attacker to execute code over a network.

Published: 2026-01-13 Last update: 2026-02-05 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-21226 is rated Moderate Risk (61.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.70%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-21226

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-15 1.70% 2.70% +1.00%
2 2026-03-22 1.47% 1.70% +0.23%
3 2026-02-28 — 1.47% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-21226

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.6 5.9 [email protected]

Weakness enumeration for CVE-2026-21226

GitHub Security Advisory for CVE-2026-21226

GHSA-jm66-cg57-jjv5 · Severity: high · Ecosystem: pip — Azure Core is vulnerable to deserialization of untrusted data

OS Trackers for CVE-2026-21226

vendor priority summary link
suse high CVE-2026-21226 severity important: SUSE including 13 source package names (13.2-9.1:perl-5.38.2-2.1, 13.2-9.1:perl-base-5.38.2-2.1, …), 36 product×package rows across 24 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (24 product lines)): Fixed 36. https://www.suse.com/security/cve/CVE-2026-21226/

Affected software / configurations for CVE-2026-21226

Vendor Product Version Raw CPE
microsoft azure_core_shared_client_library >= 1.1.0, < 1.38.0 cpe:2.3:a:microsoft:azure_core_shared_client_library:*:*:*:*:*:python:*:*

References for CVE-2026-21226

cvelogic Threat Intelligence