Staging Environment: Content and features may be unstable or change without notice.
Advisory details: pypa / nltk/PYSEC-2026-3789
Advisory ID pypa/nltk/PYSEC-2026-3789
Aliases CVE-2026-62384
GHSA-f833-7jw8-xwrv
PYSEC-2026-3789
Summary NLTK versions before 3.10.2 contain a symlink-based sandbox bypass in FramenetCorpusReader that allows attackers to read arbitrary XML files outside the corpus root. Attackers can place symlinks with names containing no path separators inside the corpus subdirectory, which pass the path validation guard and are resolved to files outside the intended corpus root when accessed via frame_by_name(), _lu_file(), or doc() methods.
Status Published
Exploitability 0.5
Weighted Severity 7.8
Risk 3.9
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 8.7 https://github.com/pypa/advisory-database/blob/main/vulns/nltk/PYSEC-2026-3789.yaml
Reference id Reference type URL
https://github.com/nltk/nltk/security/advisories/GHSA-f833-7jw8-xwrv
https://www.vulncheck.com/advisories/nltk-framenetcorpusreader-symlink-sandbox-bypass-before
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: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-2026-3789.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.