mediumCVSS 3.7Vulnerability
GHSA-3m7f-6hxv-6796
## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-8mpw-7fpc-4gqj.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.
Properties
- ghsa_id
- GHSA-3m7f-6hxv-6796
- severity
- medium
- summary
- Duplicate Advisory: Pl196xCorpusReader has quadratic ReDoS on malformed TEI blocks
- cvss_score
- 3.7
- cve_id
- GHSA-3m7f-6hxv-6796
- cvss_vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
- is_ghsa_only
- true
- ghsa_published
- 2026-08-27T18:32:30Z
- source_url
- https://github.com/advisories/GHSA-3m7f-6hxv-6796
- ghsa_updated
- 2026-09-02T14:49:57Z
Related Entities (4)
VULNERABLE_TO (1)
←[Software]pip/nltk
AFFECTS (1)
→[Software]pip/nltk
HAS_WEAKNESS (1)
→[Weakness]Uncontrolled Resource Consumption
REPORTED_BY (1)
→[Source]GitHub Advisory Database
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