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.
References
Configurations
No configuration.
History
29 Oct 2026, 20:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-10-29 20:17
Updated : 2026-10-30 17:18
NVD link : CVE-2026-119194
Mitre link : CVE-2026-119194
CVE.ORG link : CVE-2026-119194
JSON object : View
Products Affected
No product.
CWE
CWE-407
Inefficient Algorithmic Complexity
