7.5
High
CVE-2026-119194 pyasn1 is a generic ASN.1 library for Python
Description
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 tag IDs whose TagSet hashes collide. Each later set insertion compares against an increasing number of earlier colliding tags in ConstructedPayloadDecoderBase._decodeComponentsSchemaless, producing quadratic CPU work while decoded values and order remain valid. Repeated inputs can exhaust decoder CPU and reduce service availability. This issue is fixed in version 0.6.5.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| pyasn1 0.3 | 0.3.3 → < 0.6.5 | 0.6.5 |
References
- github.com github.com
- github.com github.com
- github.com github.com
- github.com github.com
Timeline
- Published
- Last modified
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The 9 CVEs of pyasn1 →
CVE-2026-119197
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CVE-2026-119196
pyasn1: Quadratic CPU consumption in constructed BIT STRING decoding
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CVE-2026-119195
pyasn1 is a generic ASN.1 library for Python
7.5
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CVE-2026-59884
pyasn1 is a generic ASN.1 library for Python
7.5
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