CVE-2026-59886
Published:July 14, 2026
Updated:August 04, 2026
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the univ.Real type converted its mantissa, base, and exponent value to a Python float using exact big-integer exponentiation. A BER, CER, or DER encoded REAL value only a few bytes long can carry a very large exponent, causing float conversion through prettyPrint(), str(), comparison, arithmetic, int(), or an explicit float() call to consume excessive CPU and memory and hang applications that decode untrusted ASN.1 data and then print, log, or compare decoded objects. This issue is fixed in version 0.6.4.
Affected Packages
pyasn1 (CONDA):
Affected version(s) >=0.1.4 <0.6.4Fix Suggestion:
Update to version 0.6.4pyasn1 (CONDA):
Affected version(s) >=0.1.4 <0.6.4Fix Suggestion:
Update to version 0.6.4https://github.com/pyasn1/pyasn1.git (GITHUB):
Affected version(s) >=v0.2.1 <v0.6.4Fix Suggestion:
Update to version v0.6.4pyasn1 (PYTHON):
Affected version(s) >=0.0.6a <0.6.4Fix Suggestion:
Update to version 0.6.4pyasn1 (PYTHON):
Affected version(s) >=0.0.6a <0.6.4Fix Suggestion:
Update to version 0.6.4Related Resources (6)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
EPSS
Base Score:
0.34