🟡 Medium | Source: Microsoft Security Response Center
CVE-2026-59886 is a vulnerability in pyasn1, a Python library used for encoding and decoding ASN.1 data structures, where processing certain REAL (floating-point) values can cause uncontrolled resource consumption. An attacker able to supply crafted input could trigger excessive CPU or memory usage, leading to a denial-of-service condition. Microsoft has published this advisory in the context of Azure, suggesting the library or affected components are present in Azure services or tooling.
Security Architect’s Take: Identify any Azure services, pipelines, or workloads that rely on pyasn1 for certificate or protocol parsing, and ensure the library is updated to a patched version. Additionally, review any externally exposed endpoints that process ASN.1-encoded data, as these represent the highest-risk attack surface.
Original advisory: CVE-2026-59886 pyasn1: Uncontrolled resource consumption when converting decoded REAL values