{"schema_version":"1.7.2","id":"OESA-2026-1776","modified":"2026-03-27T14:07:53Z","published":"2026-03-27T14:07:53Z","upstream":["CVE-2026-30922"],"summary":"python-pyasn1 security update","details":"Abstract Syntax Notation One (ASN.1) is a technology for exchanging structured data in a universally understood, hardware agnostic way. Many industrial, security and telephony applications heavily rely on ASN.1. The pyasn1 library implements ASN.1 support in pure-Python.\r\n\r\nSecurity Fix(es):\n\nThe `pyasn1` library is vulnerable to a Denial of Service (DoS) attack caused by uncontrolled recursion when decoding ASN.1 data with deeply nested structures. An attacker can supply a crafted payload containing nested `SEQUENCE` (`0x30`) or `SET` (`0x31`) tags with Indefinite Length (`0x80`) markers. This forces the decoder to recursively call itself until the Python interpreter crashes with a `RecursionError` or consumes all available memory (OOM), crashing the host application. The vulnerability exists in the `indefLenValueDecoder`, `valueDecoder`, and `_decodeComponentsSchemaless` functions, which recursively invoke the decoding callback `decodeFun` without passing a `depth` parameter or checking against a global `MAX_ASN1_NESTING` limit. Any service using `pyasn1` to parse untrusted ASN.1 data (e.g., LDAP, SNMP, Kerberos, X.509 parsers) can be crashed remotely.(CVE-2026-30922)","affected":[{"package":{"ecosystem":"openEuler:24.03-LTS-SP3","name":"python-pyasn1","purl":"pkg:rpm/openEuler/python-pyasn1&distro=openEuler-24.03-LTS-SP3"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.5.1-3.oe2403sp3"}]}],"ecosystem_specific":{"noarch":["python-pyasn1-help-0.5.1-3.oe2403sp3.noarch.rpm","python3-pyasn1-0.5.1-3.oe2403sp3.noarch.rpm"],"src":["python-pyasn1-0.5.1-3.oe2403sp3.src.rpm"]}}],"references":[{"type":"ADVISORY","url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-1776"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-30922"}],"database_specific":{"severity":"High"}}