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HIGH

CVE-2026-59884

CVSS v3

7.5

HIGH

EPSS Score

0.6 %

exploit probability, as of 2026-10-17

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • pyasn1PyPIall versions · fixed in 0.6.4

Vendor advisories

  • CVE-2026-59884 Red Hat Product Security57 products fixed · 106 known affected

    python-pyasn1: pyasn1: Denial of Service via crafted BER input

    exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 as a component of Exploit Intelligence · lightspeed-core/lightspeed-stack-rhel9 as a component of Lightspeed Core · mta/mta-rhel9-operator as a component of Migration Toolkit for Applications 8

  • RHSA-2026:83121 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Red Hat AI Inference 3.4.6 (rocm)

  • RHSA-2026:73987 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: RHOAI 3.3.7 - Red Hat OpenShift AI

  • RHSA-2026:62336 Red Hat Product Security5 products fixed

    Red Hat Security Advisory: Red Hat Enterprise Linux AI 3.3.6 enhancement update

  • RHSA-2026:62335 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Red Hat Enterprise Linux AI 3.3.6 enhancement update

  • RHSA-2026:60520 Red Hat Product Security41 products fixed

    Red Hat Security Advisory: RHOAI 3.4.4 - Red Hat OpenShift AI

2 more advisories

Full record on NVD

Description

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating continuation octets without an upper bound on the tag ID size, allowing a crafted input to force construction of an arbitrarily large integer with CPU cost growing quadratically and to trigger unhandled ValueError exceptions in Python 3.11+ error formatting paths. Any application decoding untrusted BER, CER, or DER input is affected. This issue is fixed in version 0.6.4.

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-07-14
Last Modified
2026-07-15
GitHub Advisory
GHSA-m4p7-r5rc-7g4j

Frequently asked questions

What is CVE-2026-59884?

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating continuation octets without an upper bound on the tag ID size, allowing a crafted input to force construction of an arbitrarily large integer with CPU cost growing quadratically and to trigger unhandled ValueError exceptions in Python 3.11+ error formatting paths. Any application decoding untrusted BER, CER, or DER input is affected. This issue is fixed in version 0.6.4.

Is CVE-2026-59884 actively exploited?

Active exploitation of CVE-2026-59884 has not been confirmed. Its EPSS score was 0.6% on 2026-10-17, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-59884?

CVE-2026-59884 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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