Azure Core is vulnerable to deserialization of untrusted data

HIGH 7.5CVE-2026-21226 · GHSA-jm66-cg57-jjv5 · PYSEC-2026-1208 · Published 13/01/2026 · updated 17/06/2026

In short

CVE-2026-21226 is a HIGH (CVSS 7.5) vulnerability affecting azure-core, azure core shared client library (microsoft).
Chance of exploitation in the next 30 days (EPSS): 0.95%, higher than 61.4% of all vulnerabilities.
Fix: update to 1.38.0 or later.

Package	Affected versions	Patched versions
azure-core PyPI	`< 1.38.0`	`1.38.0`
azure core shared client library microsoft	`≥ 1.1.0, < 1.38.0`	`1.38.0`

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

NVD description

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

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