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Advisory details: pypa / nltk/PYSEC-2026-3731
Advisory ID pypa/nltk/PYSEC-2026-3731
Aliases CVE-2026-65915
GHSA-72r2-7mfr-5xr9
PYSEC-2026-3731
Summary NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open() where the sandbox validation check compares a normalized path against itself, making the security check permanently inert. Attackers can pass file:// URLs to nltk.data.load() to read arbitrary files accessible to the process user, including credentials and configuration files.
Status Published
Exploitability 0.5
Weighted Severity 6.4
Risk 3.2
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (0)
There are no known CWE.
System Score Found at
cvssv4 7.1 https://github.com/pypa/advisory-database/blob/main/vulns/nltk/PYSEC-2026-3731.yaml
Reference id Reference type URL
https://github.com/nltk/nltk/security/advisories/GHSA-72r2-7mfr-5xr9
https://www.vulncheck.com/advisories/nltk-before-arbitrary-file-read-via-filesystempathpointer
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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 Found at https://github.com/pypa/advisory-database/blob/main/vulns/nltk/PYSEC-2026-3731.yaml
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

There are no SSVC decisions available.