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Advisory details: pypa / nltk/PYSEC-2026-3737
Advisory ID pypa/nltk/PYSEC-2026-3737
Aliases CVE-2026-79676
GHSA-p4rw-rvv2-7xwr
PYSEC-2026-3737
Summary NLTK versions before 3.10.3 contain a path traversal vulnerability in corpus readers that reopen root-derived paths using built-in open() instead of nltk.pathsec.open(), allowing symlinks to escape trusted roots. Attackers who stage symlinked corpus files under a trusted data root can disclose outside-root content through normal corpus reader methods like channels(), domains(), and synonyms().
Status Published
Exploitability 0.5
Weighted Severity 7.4
Risk 3.7
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 8.2 https://github.com/pypa/advisory-database/blob/main/vulns/nltk/PYSEC-2026-3737.yaml
Reference id Reference type URL
GHSA-p4rw-rvv2-7xwr Advisory https://github.com/nltk/nltk/security/advisories/GHSA-p4rw-rvv2-7xwr
nltk-before-path-traversal-via-symlink-bypass Advisory https://www.vulncheck.com/advisories/nltk-before-path-traversal-via-symlink-bypass
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:H/AT:P/PR:N/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-2026-3737.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.