pyasn1 has quadratic CPU use in schemaless BER/CER/DER container decoding

Summary When an application decodes attacker-controlled BER, CER, or DER data without an ASN.1 schema, a container with many distinct long tag IDs can cause quadratic CPU use. Repeated inputs can exhaust CPU and reduce service availability. Details...

GHSA-FM9C-5RCF-2Q5P pyasn1 has quadratic CPU use in schemaless BER/CER/DER container decoding

Summary When an application decodes attacker-controlled BER, CER, or DER data without an ASN.1 schema, a container with many distinct long tag IDs can cause quadratic CPU use. Repeated inputs can exhaust CPU and reduce service availability. Details...

CVE-2026-119194 pyasn1: Quadratic CPU use in schemaless BER/CER/DER container decoding

pyasn1 is a generic ASN.1 library for Python. From 0.3.3 until 0.6.5, schemaless container decoding stores every decoded component's TagSet in a growing set even though only one-versus-multiple tag types must be distinguished. Attacker-controlled BER, CER, or DER input contains many distinct long...

CVE-2026-119194

The pyasn1 Python library (versions 0.3.3 through 0.6.5 ) is vulnerable to a quadratic CPU use issue during schemaless BER, CER, or DER container decoding. The root cause lies in the ConstructedPayloadDecoderBase._decodeComponentsSchemaless function, where the application stores every decoded com...

CVE-2026-119194 pyasn1: Quadratic CPU use in schemaless BER/CER/DER container decoding

pyasn1 is a generic ASN.1 library for Python. From 0.3.3 until 0.6.5, schemaless container decoding stores every decoded component's TagSet in a growing set even though only one-versus-multiple tag types must be distinguished. Attacker-controlled BER, CER, or DER input contains many distinct long...

pyasn1: pyasn1: Denial of Service via crafted ASN.1 REAL values

A remote attacker can exploit this by providing specially crafted BER/CER/DER-encoded ASN.1 data with a large exponent in the REAL value. When the application subsequently prints, logs, compares, or performs arithmetic on the decoded value, this can cause excessive CPU and memory consumption,...

pyasn1: pyasn1: Denial of Service via crafted ASN.1 REAL values

A remote attacker can exploit this by providing specially crafted BER/CER/DER-encoded ASN.1 data with a large exponent in the REAL value. When the application subsequently prints, logs, compares, or performs arithmetic on the decoded value, this can cause excessive CPU and memory consumption,...

pyasn1: pyasn1: Denial of Service via crafted ASN.1 REAL values

A remote attacker can exploit this by providing specially crafted BER/CER/DER-encoded ASN.1 data with a large exponent in the REAL value. When the application subsequently prints, logs, compares, or performs arithmetic on the decoded value, this can cause excessive CPU and memory consumption,...

Important: python-pyasn1

Issue Overview: pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating continuation octets without an upper bound on the tag ID size, allowing a crafted input to force construction of an arbitrarily larg...