CVEvulnerability

CVE-2026-81727

6.9 MEDIUM Published 2026-08-27 Modified 2026-08-31 Official page ↗
Status
Analyzed
Published
2026-08-27
Last modified
2026-08-31
Assigner
[email protected]
CVSS 4.0 ([email protected])
6.9 MEDIUM — CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/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
CVSS 3.1 ([email protected])
7.1 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Weaknesses
CWE-59

Description

NLTK versions before 3.10.3 contain a filesystem containment bypass vulnerability in the Downloader.download and Downloader.incr_download methods that allows attackers to overwrite files outside the install root through pre-existing hardlinks. Attackers with write access to a shared downloader directory can create hardlinks pointing to outside-root files that are then overwritten during normal package extraction, mutating files outside the intended install tree.

Affected configurations

• nltk nltk (< 3.10.3)

Related

Weakness · CWE (1)

  • CWE-59 Improper Link Resolution Before File Access weakness

References