Description
unicodedata.normalize() can take excessive CPU time when processing
specially crafted Unicode input containing long runs of combining characters
with alternating Canonical Combining Class values.
This affects all normalization forms.
Published: 2026-06-03
Score: 6.3 Medium
EPSS: < 1% Very Low
KEV: No
AI Analysis

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Remediation

No solution or workaround provided in the CVE record.

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4827-1 python3.11 security update
Ubuntu USN Ubuntu USN USN-8509-1 Python vulnerabilities
History

Tue, 11 Aug 2026 02:45:00 +0200


Wed, 05 Aug 2026 03:00:00 +0200


Tue, 16 Jun 2026 17:00:00 +0200


Fri, 05 Jun 2026 12:45:00 +0200

Type Values Removed Values Added
First Time appeared Python
Python cpython
Vendors & Products Python
Python cpython

Thu, 04 Jun 2026 19:45:00 +0200


Thu, 04 Jun 2026 02:15:00 +0200

Type Values Removed Values Added
Weaknesses CWE-606
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

threat_severity

Moderate


Wed, 03 Jun 2026 22:30:00 +0200

Type Values Removed Values Added
References

Wed, 03 Jun 2026 20:30:00 +0200

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 03 Jun 2026 18:00:00 +0200

Type Values Removed Values Added
Description unicodedata.normalize() can take excessive CPU time when processing specially crafted Unicode input containing long runs of combining characters with alternating Canonical Combining Class values. This affects all normalization forms.
Title Potential DoS via quadratic complexity in unicodedata.normalize()
Weaknesses CWE-407
References
Metrics cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: PSF

Published:

Updated: 2026-08-13T00:28:05.768Z

Reserved: 2026-02-26T15:19:46.862Z

Link: CVE-2026-3276

cve-icon Vulnrichment

Updated: 2026-06-03T19:18:17.828Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-06-03T16:16:29.253

Modified: 2026-08-13T01:16:52.847

Link: CVE-2026-3276

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-06-03T14:29:39Z

Links: CVE-2026-3276 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-06-05T12:11:33Z

Weaknesses
  • CWE-407

    Inefficient Algorithmic Complexity

  • CWE-606

    Unchecked Input for Loop Condition