GHSA-3m7f-6hxv-6796

Duplicate Advisory: Pl196xCorpusReader has quadratic ReDoS on malformed TEI blocks

Published

2026-08-27

Modified

2026-09-02

Sources

github-advisory

Summary

## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-8mpw-7fpc-4gqj. This link is maintained to preserve external references. ## Original Description 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.

Affected packages

Remediation: No patched version is listed by GitHub.

References

• https://github.com/advisories/GHSA-3m7f-6hxv-6796