CVE-2026-70626: high-severity vulnerability in nltk
NLTK before 3.9.4 Symlink Escape via CorpusReader
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 0.2%
NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place symlinks inside the corpus root to access files outside the intended boundary.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
nltk · nltkRelated CVEs — nltk
In the same product, most dangerous first.
CVE-2021-43854HIGHInefficient Regular Expression Complexity in nltkEPSS 2.8%CVE-2026-79657CRITICALNLTK before 3.10.3 Remote Code Execution via Unsafe Pickle DeserializationEPSS 1.3%CVE-2026-33231HIGHNLTK has unauthenticated remote shutdown in nltk.app.wordnet_appEPSS 1.3%CVE-2026-71513HIGHNLTK 3.10.0 through 3.10.2 Remote Code Execution via AllowlistUnpickler Dotted-Name BypassEPSS 1.1%CVE-2026-79675CRITICALNLTK before 3.10.3 JVM Argument Injection via Per-Call OptionsEPSS 0.8%CVE-2026-72818HIGHNLTK TweetTokenizer URL Pattern Backtracks Catastrophically on Naked-Domain-Like InputEPSS 0.7%