Vulnerability 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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/pyasn1/pyasn1/commit/a36e3a3d067148d26197a6b7221fd0e2cde9cc86
- https://github.com/pyasn1/pyasn1/pull/132
- https://github.com/pyasn1/pyasn1/releases/tag/v0.6.5
- https://github.com/pyasn1/pyasn1/security/advisories/GHSA-fm9c-5rcf-2q5p
FAQ
What is CVE-2026-119194?
CVE-2026-119194 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 ty...
How severe is CVE-2026-119194?
CVE-2026-119194 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-119194?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.