Staging Environment: Content and features may be unstable or change without notice.
Advisory details: github_osv / GHSA-8h9m-22mv-qv5r
Advisory ID github_osv/GHSA-8h9m-22mv-qv5r
Aliases
Summary Duplicate Advisory: Symlink escape in CorpusReader allows arbitrary local file read outside the corpus root ## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-r6gq-whwq-mvg9. This link is maintained to preserve external references. ## Original Description NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place symlinks inside the corpus root to access files outside the intended boundary.
Status Published
Exploitability 0.5
Weighted Severity 7.7
Risk 3.9
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
CWE-59 Improper Link Resolution Before File Access ('Link Following')
System Score Found at
cvssv3.1 6.2 https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-8h9m-22mv-qv5r/GHSA-8h9m-22mv-qv5r.json
cvssv4 8.6 https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-8h9m-22mv-qv5r/GHSA-8h9m-22mv-qv5r.json
generic_textual HIGH
Reference id Reference type URL
https://github.com/nltk/nltk/security/advisories/GHSA-r6gq-whwq-mvg9
https://www.vulncheck.com/advisories/nltk-before-symlink-escape-via-corpusreader
CVE-2026-70626 https://nvd.nist.gov/vuln/detail/CVE-2026-70626
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-8h9m-22mv-qv5r/GHSA-8h9m-22mv-qv5r.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/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 Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-8h9m-22mv-qv5r/GHSA-8h9m-22mv-qv5r.json
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.