pyasn1

pyasn1 is a pure-Python implementation of ASN.1 types and BER/DER/CER codecs (X.208). It lets developers define ASN.1 schemas as Python classes, then encode/decode wire-format bytes for network protocols and file formats such as X.509 certificates, PKCS structures, SNMP, and LDAP. Current version is 0.6.3 (released 2026), which adds a nesting depth limit to prevent stack overflow (CVE-2026-30922) and fixes an OverflowError from oversized BER length fields. The project is maintained by Christian Heimes and Simon Pichugin under the github.com/pyasn1 organisation following ownership transfer at v0.5.0; releases are irregular but active, with multiple releases per year addressing security CVEs and Python version support.