Inefficient Algorithmic Complexity Affecting pyasn1 package, versions [0.3.3,0.6.5)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-PYASN1-22113911
- published1 Nov 2026
- disclosed30 Oct 2026
- creditSimon Pichugin
Introduced: 30 Oct 2026
NewCVE-2026-119194 (opens in a new tab)How to fix?
Upgrade pyasn1 to version 0.6.5 or higher.
Overview
Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity in the ConstructedPayloadDecoderBase._decodeComponentsSchemaless method in pyasn1/codec/ber/decoder.py. An attacker can exhaust CPU during a schemaless decode() of a BER, CER, or DER container by supplying many components whose long tag IDs produce colliding TagSet hashes, so each component's insertion into the growing classification set compares against all earlier entries. Exploitation requires the application to decode attacker-controlled data without an ASN.1 schema, since the schema-driven path does not build this classification set.