CVE-2026-119194

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.
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