Fluid Attacks Database

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.

Mitigation

Update Impact

Minimal update. May introduce new vulnerabilities or breaking changes.

Ecosystem	Component	Affected version	Patched versions
debian 11	nltk	=3.10.0-1 \|\| =3.10.1-1 \|\| =3.10.3-1 \|\| =3.5-1 \|\| =3.6.5-1 \|\| =3.6.7-1 \|\| =3.7-1 \|\| =3.8-1 \|\| =3.8.1-1 \|\| =3.9.1-1 \|\| =3.9.1-2 \|\| =3.9.2-1 \|\| =3.9.3-1	-
debian 14	nltk	=3.10.0-1 \|\| =3.10.1-1 \|\| =3.9.1-2 \|\| =3.9.2-1 \|\| =3.9.3-1 \|\| >=0 <3.10.3-1	3.10.3-1
debian 12	nltk	=3.10.0-1 \|\| =3.10.1-1 \|\| =3.10.3-1 \|\| =3.8-1 \|\| =3.8.1-1 \|\| =3.9.1-1 \|\| =3.9.1-2 \|\| =3.9.2-1 \|\| =3.9.3-1	-
debian 13	nltk	=3.10.0-1 \|\| =3.10.1-1 \|\| =3.10.3-1 \|\| =3.9.1-2 \|\| =3.9.2-1 \|\| =3.9.3-1	-

Aliases

1. CVE-2026-786812. NVD-2026-786813. OSV-DEBIAN-2026-786814. OSV-2026-786815. SECURITY-TRACKER-CVE-2026-78681

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