This page tracks the Debian fix status. The vulnerability itself is described on the main CVE page. View CVE-2026-81725 →

DEBIAN-CVE-2026-81725

NLTK before 3.10.3 contains a regular expression denial of service vulnerability in Pl196xCorpusReader that allows attackers to cause quadratic CPU co...

Original description

The description as published by the source.

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.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Affected packages

Debian:12 nltk

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Debian:13 nltk

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Debian:14 nltk

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.10.3-1"}]}]

References

advisory security-tracker.debian.org