NLTK up to 3.10.2 XMLCorpusView XMLCorpusView._read_xml_fragment resource consumption

Summaryinfo

A vulnerability described as problematic has been identified in NLTK up to 3.10.2. The impacted element is the function XMLCorpusView._read_xml_fragment of the component XMLCorpusView. The manipulation results in resource consumption. This vulnerability is reported as CVE-2026-81723. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, was found in NLTK up to 3.10.2. Affected is the function XMLCorpusView._read_xml_fragment of the component XMLCorpusView. The manipulation with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-81723 since 08/27/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

The vulnerability scanner Nessus provides a plugin with the ID 341146 (Linux Distros Unpatched Vulnerability : CVE-2026-81723), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.10.3 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (341146). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

• NLTK

Version

• 3.10.0
• 3.10.1
• 3.10.2

Website

• Product: https://github.com/nltk/nltk/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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