Staging Environment: Content and features may be unstable or change without notice.
Advisory details: github_osv / GHSA-vp9c-2pjm-8925
Advisory ID github_osv/GHSA-vp9c-2pjm-8925
Aliases
Summary Duplicate Advisory: Allowlisted pickle loaders still permit code execution in current source ## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-x99w-6fgc-pmfw. This link is maintained to preserve external references. ## Original Description NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific safe callables. Attackers can craft malicious pickle payloads invoking dangerous in-namespace functions like ReppTokenizer._execute and numpy.f2py.crackfortran.myeval through pickle REDUCE to execute arbitrary commands during model or tokenizer artifact loading.
Status Published
Exploitability 0.5
Weighted Severity 8.8
Risk 4.4
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
CWE-502 Deserialization of Untrusted Data
System Score Found at
cvssv3.1 9.8 https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-vp9c-2pjm-8925/GHSA-vp9c-2pjm-8925.json
cvssv4 9.3 https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-vp9c-2pjm-8925/GHSA-vp9c-2pjm-8925.json
generic_textual CRITICAL
Reference id Reference type URL
CVE-2026-79657 https://nvd.nist.gov/vuln/detail/CVE-2026-79657
GHSA-x99w-6fgc-pmfw Advisory https://github.com/nltk/nltk/security/advisories/GHSA-x99w-6fgc-pmfw
nltk-before-3.10.3-remote-code-execution-via-unsafe-pickle-deserialization Advisory https://www.vulncheck.com/advisories/nltk-before-3.10.3-remote-code-execution-via-unsafe-pickle-deserialization
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-vp9c-2pjm-8925/GHSA-vp9c-2pjm-8925.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:N/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-vp9c-2pjm-8925/GHSA-vp9c-2pjm-8925.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.