CVE-2026-81723

NLTK before 3.10.3 Quadratic CPU Exhaustion via XMLCorpusView

LOW
3.7
CVSS Score
Published: August 27, 2026 at 02:51 PM UTC
Updated: September 24, 2026 at 08:57 PM UTC
1 product affected across 1 vendorNltk

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Severity
LOW3.7
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

NLTK versions before 3.10.3 contain a quadratic CPU exhaustion vulnerability in XMLCorpusView._read_xml_fragment() that rescans accumulated XML fragments on every 1 KiB block read. Attackers can provide malformed XML corpus files to cause severe CPU consumption and denial of service through affected readers like BNCCorpusReader.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.10.3
Vendor states this is fixed in 3.10.3 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

3.7LOWVulnCheck
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-400

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