CVE-2026-109956: nltk Path Traversal
CVSS: 8.3v4.0HighAwaiting analysis
AliasesDEBIAN-CVE-2026-109956UBUNTU-CVE-2026-109956
Published 13-10-2026Last modified 13-10-2026
Vulnerability summary
CVE-2026-109956 is a high (CVSS 8.3) Path Traversal vulnerability in nltk. EPSS estimates a 0.32% chance of exploitation in the next 30 days, higher than 23.1% of scored vulnerabilities.
CVSS score
8.3/10
010
High · v4.0 (CVE.org)EPSS score
0.32%
0%100%
Low · Change unavailableKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 13-10-2026PublishedVulnerability first disclosed.
Description
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.
CVSS metrics
7 scores · 4 sources · 2 versionsHigh 8.3Preferred score · CVE.org (CNA)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:NSourcesAll 3 agree
- NVDNIST8.3HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · UbuntuEcosystem advisory · calculated8.3HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N
High 7.0Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:LSourcesAll 4 agree
- NVDNIST7.0HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L
- OSV · DebianEcosystem advisory · calculated7.0HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L
- OSV · UbuntuEcosystem advisory · calculated7.0HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L
EPSS trend
Probability
0.32%
Chance of exploitation in the next 30 days
Percentile
23%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
14-10-202618-10-2026
EPSS score0.32%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian1 product
- nltkAll versions (No fix recorded)
Nltk1 product
- nltk≤ 3.10.3
Ubuntu1 product
- nltkAll versions (No fix recorded)
3 vendors · 3 products
References
5 links- www.vulncheck.com/advisories/nltk-through-3.10.3-path-traversal-via-wekaclassifier-model-pathThird Party AdvisoryREPORT
