CVE-2026-3276: Potential DoS via quadratic complexity in unicodedata.normalize()

unknownCVE-2026-3276

CSIRTS triage

vendor: Python product: Python Denial of service

What: Potential DoS can occur via quadratic complexity in unicodedata.normalize().
Who is affected: Users of Python that utilize the unicodedata module.
Urgency: This issue is of unknown severity but could lead to denial of service, warranting attention.
Action: Monitor for updates or apply mitigations as necessary.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: unknown
Published: 2026-06-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-3276

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-32760.49% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 39% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-3276	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

medium[UPDATE] [medium] CPython: Multiple vulnerabilitiescert-bund
unknownUSN-8509-1: Python vulnerabilitiesubuntu

Recent advisories for Potential DoS via

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highGHSA-qcq2-496w-v96p: Mistune: Potential DoS via quadratic-time parsing in parse_link_textghsa · 2026-07-09
unknownCVE-2026-49851: Mistune: Potential DoS via quadratic-time parsing in parse_link_textmsrc · 2026-06-09