---
title: "CVE-2026-79675: NLTK: JVM argument injection bypass via per-call options in the NLTK Stanford wrappers (incomplete fix of CVE-2026-12841)"
url: https://erroneo.us/security/cve/CVE-2026-79675/
description: "CVE-2026-79675 (nltk (PyPI)): NLTK before 3.10.3 fails to validate JVM options passed through the per-call options parameter in the java() function…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-08-25
date_modified: 2026-09-01
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-79675"
kev: false
cvss: 9.3
epss: 0.00775
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-79675: NLTK: JVM argument injection bypass via per-call options in the NLTK Stanford wrappers (incomplete fix of CVE-2026-12841)

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.8% , percentile 55: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 55% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes nltk (PyPI) <= 3.10.2, fixed in 3.10.3 . Check your lockfile, including transitive dependencies.

## What it is

NLTK before 3.10.3 fails to validate JVM options passed through the per-call options parameter in the java() function, allowing attackers to inject dangerous JVM flags. Attackers can supply malicious options like -agentpath, -javaagent, or @argfile to Stanford wrapper classes to achieve arbitrary code execution.

## Affected packages

- PyPI `nltk` <= 3.10.2 → fixed: 3.10.3

## Affected products (CVE record)

- nltk nltk: < 3.10.3

## Severity

- VulnCheck CVSS 4.0: 9.3 `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`
- VulnCheck CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 4.0: 9.3 `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`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.78% probability of exploitation activity in the next 30 days; percentile 55.

## Sources

- [GitHub Security Advisory (GHSA-m4rf-3fr8-xwx3)](https://github.com/nltk/nltk/security/advisories/GHSA-m4rf-3fr8-xwx3)
- [GitHub Advisory GHSA-m4rf-3fr8-xwx3](https://github.com/advisories/GHSA-m4rf-3fr8-xwx3)
- [CVE.org record CVE-2026-79675](https://www.cve.org/CVERecord?id=CVE-2026-79675)
- [NVD entry CVE-2026-79675](https://nvd.nist.gov/vuln/detail/CVE-2026-79675)
- [VulnCheck Advisory: NLTK before 3.10.3 JVM Argument Injection via Per-Call Options](https://www.vulncheck.com/advisories/nltk-before-jvm-argument-injection-via-per-call-options)
- [github.com](https://github.com/nltk/nltk/commit/8fa9650b6009aacfdebbc33d2a08d32c0858ea6c)
- [github.com](https://github.com/nltk/nltk/releases/tag/v3.10.3)

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Source page: https://erroneo.us/security/cve/CVE-2026-79675/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt