Resource Exhaustion Affecting nltk package, versions <3.10.3-1


Severity

Recommended
0.0
low
0
10

Snyk's Security Team recommends NVD's CVSS assessment. Learn more

Threat Intelligence

EPSS
0.22% (13th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-NLTK-19385589
  • published28 Aug 2026
  • disclosed27 Aug 2026

Introduced: 27 Aug 2026

NewCVE-2026-81725  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

Upgrade Debian:unstable nltk to version 3.10.3-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nltk package and not the nltk package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

NLTK before 3.10.3 contains a regular expression denial of service vulnerability in Pl196xCorpusReader that allows attackers to cause quadratic CPU consumption by supplying malformed TEI blocks with many unmatched opening tags. Attackers can exploit lazy regex patterns in the read_block method through public APIs like words() and tagged_words() to force repeated rescans and achieve near-quadratic runtime growth.

CVSS Base Scores

version 3.1