Bug 2550515 (CVE-2026-109956)

Summary: CVE-2026-109956 nltk: nltk: Arbitrary file write via path traversal in WekaClassifier
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: anpicker, bparees, dschmidt, ebourniv, hasun, ikhan, jfula, jlanda, jowilson, kshier, nyancey, ometelka, ptisnovs, rbobbitt, sbunciak, simaishi, stcannon, syedriko, xdharmai, yguenane
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in NLTK. A path traversal vulnerability in the WekaClassifier module allows an attacker to bypass directory containment restrictions by supplying unvalidated model paths. By controlling these path arguments, an attacker can write arbitrary files or probe existing files outside of permitted directories.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-13 13:51:24 UTC
NLTK through 3.10.3 contains a path traversal vulnerability in WekaClassifier that allows attackers to bypass nltk.pathsec containment by supplying unvalidated model paths. Attackers controlling the model_filename or model argument can make the weka JVM write files via -d or probe files via -l outside allowed data roots.