CVE-2026-109956

waiting for further signalsZero needs more public information before it can validate it.

GHSA-9fgx-q9j8-3j83 ↗EUVD-2026-98660 ↗

no check availablenot proven exploitable
cve.orgpublic pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).−15dkevAttacks confirmed in the real world.
nltk <= 3.10.3
CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
ETK-2026-1472Zero's internal tracking ID, independent of the CVE number., permanent identifier
pkg:pypi/nltk
7d 14h 41msince last run
11mAI analysisAnalysis: how long the AI spent reversing this signal.
timeline
0 = cve.org publication
trigger signal −15dpublic poc−15dcve.org publicationwaiting for further signals+0.1d
−10d
−5d

description

NLTK releases through 3.10.3 are affected in the WekaClassifier component. An attacker who can control model-path inputs may cause the Weka process to read from or write to locations outside configured data directories. Applications are exposed when untrusted users or data sources can supply these model settings.

mitigation

Do not permit untrusted input to set WekaClassifier model paths, and restrict the Weka process to a dedicated account with access only to required directories. Apply a vendor-provided update when a fixed NLTK release is published.

check
no
exploit
no
automationDeterministic: a check that runs on its own, the same request on every target. Contextual: an agentic technique that needs to be applied per target, for bugs that depend on contextual flows.
contextual
auth requiredWhether an attacker needs an account first, based on the CVSS vector's Privileges Required.
no
EPSSEstimate of the chance this CVE is exploited in the next 30 days. Refreshed daily.
0.32%23rd percentile
agent run time
11m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-10-13 13:27Z
Δ to public pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).
−15d
Δ to kevAttacks confirmed in the real world.
–

outcome

Contextual: an exploit technique exists, but no deterministic check could cover this one.

source signals

Public signals that triggered or updated the pipeline. These are inputs for the deltas above.

  1. 2026-09-29 00:52Z
  2. 2026-10-13 13:27Z
    cve_org: trigger signal, started the run

this entry in the feed

GET /api/v1/feed/CVE-2026-109956

{
  "etk_id": "ETK-2026-1472",
  "cve_id": "CVE-2026-109956",
  "display_id": "CVE-2026-109956",
  "ghsa_id": "GHSA-9fgx-q9j8-3j83",
  "euvd_id": "EUVD-2026-98660",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Path traversal in NLTK WekaClassifier",
  "summary": "NLTK releases through 3.10.3 are affected in the WekaClassifier component. An attacker who can control model-path inputs may cause the Weka process to read from or write to locations outside configured data directories. Applications are exposed when untrusted users or data sources can supply these model settings.",
  "mitigation": "Do not permit untrusted input to set WekaClassifier model paths, and restrict the Weka process to a dedicated account with access only to required directories. Apply a vendor-provided update when a fixed NLTK release is published.",
  "vendor": "nltk",
  "product": "nltk",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        "<= 3.10.3"
      ],
      "ecosystem": "pip",
      "fixed_versions": [],
      "package_name": "nltk",
      "purl": "pkg:pypi/nltk"
    }
  ],
  "cwes": [
    22
  ],
  "cvss_score": 8.3,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N",
  "epss_score": 0.0032,
  "epss_percentile": 0.2326,
  "epss_asof": "2026-10-20",
  "automation": "contextual",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 10.9907966,
  "t0_at": "2026-10-13T13:27:20.244000+00:00",
  "signals": {
    "public_poc": {
      "at": "2026-09-29T00:52:39+00:00",
      "days": -14.524088472222223,
      "is_lower_bound": false,
      "measured_at": "2026-10-13T13:27:20.244000+00:00",
      "url": "https://github.com/nltk/nltk/security/advisories/GHSA-j456-xh4h-cpf2"
    },
    "trigger_signal": {
      "at": "2026-09-29T00:52:39+00:00",
      "days": -14.524088472222223,
      "is_lower_bound": false,
      "measured_at": "2026-10-13T13:27:20.244000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-109956"
    }
  }
}

published 2026-10-13 14:48Z
last change 2026-10-21 05:31Z

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