VULNERABILITY INTELLIGENCE

CVE-2026-78681

CVSS score7.5 HIGH
EPSS probability0.52%
CISA KEVNot currently listed
Published2026-08-25
Last modified2026-10-12
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Description

NLTK versions before 3.10.3 use xml.etree.ElementTree to parse XML in multiple modules, which honors entity declarations in document DTDs. Attackers can craft XML payloads with nested entity declarations that expand from hundreds of bytes to megabytes in memory, causing denial of service.

Weakness classification

  • disclosure@vulncheck.com: CWE-776

Primary references