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© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2026-59886

36
FAUCET Score

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.

First published: Jul 14, 2026Last modified: Jul 14, 2026

Impacted Technologies

VendorProductVersion(s)CPE
< 0.6.4CPE matchmatch criteria
cpe:2.3:a:pyasn1:pyasn1:*:*:*:*:*:python:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.34%
Probability of exploitation in next 30 days
EPSS Percentile
25.9%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0034 is in the 7th percentile among its peer group of 51,553 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (3)

github_advisorypatch availablevia nvd_reference
View patch
microsoftpatch availablevia msrc
Product: azl3 python-pyasn1 0.4.8-2 on Azure Linux 3.0Fixed in: 0.4.8-3
pippatch availablevia ghsa
Product: pyasn1Fixed in: 0.6.4

Vendor Advisories (2)

pipGHSA-hm4w-wwcw-mr6rhigh

pyasn1: Uncontrolled resource consumption when converting decoded REAL values

Jul 21, 2026
microsoft2026-Jul/CVE-2026-59886Important

pyasn1: Uncontrolled resource consumption when converting decoded REAL values

Jul 14, 2026

References

github.com / pyasn1/pyasn1/commit/e60c691cb91addb8fcefa2f537e85ede6fb1e886
Patch
github.com / pyasn1/pyasn1/releases/tag/v0.6.4
Release Notes
github.com / pyasn1/pyasn1/security/advisories/GHSA-hm4w-wwcw-mr6r
Third Party Advisory