CVE-2026-59886

EUVD-2026-43738

14.07.2026, 17:17

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.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	7.5 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Base Score

CVSS 3.x

EPSS Score

Percentile: 25.9%

Affected Products (NVD)

Vendor	Product	Version
pyasn1	pyasn1	𝑥 < 0.6.4

𝑥

= Vulnerable software versions

Debian Releases

Debian Product

Codename

pyasn1

bookworm	vulnerable
bookworm (security)	vulnerable
bullseye	vulnerable
bullseye (security)	vulnerable
forky	0.6.4-1 fixed
sid	0.6.4-1 fixed
trixie	no-dsa
trixie (security)	vulnerable

Ubuntu Releases

Ubuntu Product

Codename

pyasn1

bionic	needs-triage
focal	needs-triage
jammy	needs-triage
noble	needs-triage
resolute	needs-triage
trusty	needs-triage
xenial	needs-triage

Red Hat Enterprise Linux Releases

Red Hat Product

Release

fence-agents-aliyun

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-all

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-amt-ws

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-apc

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-apc-snmp

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-aws

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-azure-arm

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-bladecenter

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-brocade

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-cisco-mds

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-cisco-ucs

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-common

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-compute

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-drac5

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-eaton-snmp

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-emerson

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-eps

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-gce

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-heuristics-ping

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-hpblade

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-ibm-powervs

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-ibm-vpc

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-ibmblade

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-ifmib

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-ilo-moonshot

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-ilo-mp

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-ilo-ssh

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-ilo2

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-intelmodular

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-ipdu

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-ipmilan

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-kdump

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-kubevirt

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-lpar

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-mpath

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-nutanix-ahv

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-openstack

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-redfish

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-rhevm

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-rsa

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-rsb

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-sbd

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-scsi

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-virsh

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-vmware-rest

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-vmware-soap

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-wti

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-agents-zvm

RHEL 8	0:4.2.1-129.el8_10.29 fixed
RHEL 9	0:4.10.0-110.el9_8.6 fixed

fence-virt

RHEL 9

0:4.10.0-110.el9_8.6

fixed

fence-virtd

RHEL 9

0:4.10.0-110.el9_8.6

fixed

fence-virtd-cpg

RHEL 9

0:4.10.0-110.el9_8.6

fixed

fence-virtd-libvirt

RHEL 9

0:4.10.0-110.el9_8.6

fixed

fence-virtd-multicast

RHEL 9

0:4.10.0-110.el9_8.6

fixed

fence-virtd-serial

RHEL 9

0:4.10.0-110.el9_8.6

fixed

fence-virtd-tcp

RHEL 9

0:4.10.0-110.el9_8.6

fixed

ha-cloud-support

RHEL 9

0:4.10.0-110.el9_8.6

fixed

resource-agents

RHEL 8

0:4.9.0-54.el8_10.37

fixed

resource-agents-aliyun

RHEL 8

0:4.9.0-54.el8_10.37

fixed

resource-agents-gcp

RHEL 8

0:4.9.0-54.el8_10.37

fixed

resource-agents-paf

RHEL 8

0:4.9.0-54.el8_10.37

fixed

Amazon Linux Releases

Amazon Package

Release

python-pyasn1-doc

Amazon Linux 2023

0:0.4.8-4.amzn2023.0.5

fixed

python2-pyasn1

Amazon Linux 2

0:0.1.9-7.amzn2.0.5

fixed

python2-pyasn1-modules

Amazon Linux 2

0:0.1.9-7.amzn2.0.5

fixed

python3-pyasn1

Amazon Linux 2	0:0.1.9-7.amzn2.0.5 fixed
Amazon Linux 2023	0:0.4.8-4.amzn2023.0.5 fixed

python3-pyasn1-modules

Amazon Linux 2	0:0.1.9-7.amzn2.0.5 fixed
Amazon Linux 2023	0:0.4.8-4.amzn2023.0.5 fixed

Azure Linux Releases

Azure Package

Release

python-pyasn1

Azure Linux 3.0

0:0.4.8-3.azl3

fixed

Common Weakness Enumeration

CWE-400 - Uncontrolled Resource Consumption
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

References

https://github.com/pyasn1/pyasn1/commit/e60c691cb91addb8fcefa2f537e85ede6fb1e886

https://github.com/pyasn1/pyasn1/releases/tag/v0.6.4

https://github.com/pyasn1/pyasn1/security/advisories/GHSA-hm4w-wwcw-mr6r