CVE-2026-78681High· 7.5▾ TwilightNLTK 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 byte…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 41.3 · likelihood 0.1 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Exploit-prediction probability, daily snapshots since Sep 2.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.3%
none → high
high → none
none → high
high → none
none → high
high → none
none → high
high → none
none → high
high → none
none → high
0.3% → 0.5%
Last analysed / modified upstream
— → 7.5
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.
nltk < 3.10.3Upgrade past the affected range:
nltk 3.10.3Affected packages:
nltk < 3.10.3Patched in:
nltk 3.10.3Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-81723Low· 3.7NLTK versions before 3.10.3 contain a quadratic CPU exhaustion vulnerability in XMLCorpusView._read_xml_fragment() that rescans accumulated XML fragments on every 1 KiB block read
CVE-2026-79657Critical· 9.8NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific safe callables
CVE-2026-78682High· 7.5NLTK before 3.10.3 contains a server-side request forgery vulnerability in nltk.pathsec.urlopen (and callers nltk.data.load, nltk.downloader.Downloader.index/download) when an HTTP proxy is configured
CVE-2026-12876MediumNLTK: Uncontrolled resource consumption in RecursiveDescentParser via ambiguous or left-recursive grammars
CVE-2026-78680High· 7.8NLTK versions before 3.10.3 fail to use validated absolute paths when invoking the Graphviz dot binary in dependencygraph.dot2img and AlignedSent._repr_svg_, allowing attackers to execute arbitrary code by placing a malicious dot binary …
CVE-2026-71514Low· 2.5NLTK 3.9.4 through 3.10.2 contains a path traversal vulnerability in CrubadanCorpusReader