HOMEVULNERABILITIESCVE-2026-33231
HIGH

CVE-2026-33231

CWE-306Published: March 20, 2026· Updated: Mar 23, 2026

7.5
CVSS v3.1
EPSS:0.04%probability of exploitation in 30 daysPercentile:12.2th

Official Description

NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, `nltk.app.wordnet_app` allows unauthenticated remote shutdown of the local WordNet Browser HTTP server when it is started in its default mode. A simple `GET /SHUTDOWN%20THE%20SERVER` request causes the process to terminate immediately via `os._exit(0)`, resulting in a denial of service. Commit bbaae83db86a0f49e00f5b0db44a7254c268de9b patches the issue.

NVD Source

Technical Analysis

CVE-2026-33231 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

nltk1 product
nltk
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/nltk/nltk/commit/bbaae83db86a0f49e00f5b0db44a7254c268de9b
ADVISORYhttps://github.com/nltk/nltk/security/advisories/GHSA-jm6w-m3j8-898g

All References (2)

→
https://github.com/nltk/nltk/commit/bbaae83db86a0f49e00f5b0db44a7254c268de9bPatch
→
https://github.com/nltk/nltk/security/advisories/GHSA-jm6w-m3j8-898gExploit · Vendor Advisory

Quick Facts

CVE IDCVE-2026-33231
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-306
CISA KEVNo
EPSS (30d)0.04%
Affected1 vendor
PublishedMar 20, 2026

Related CVEs (CWE-306)

CVE-2026-54309
10.0
CVE-2026-20223
10.0
CVE-2026-44329
10.0
CVE-2026-34162
10.0
CVE-2026-49257
10.0
CVE-2026-46803
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-33231 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
← All Vulnerabilities·Search for CVE-2026-33231·NVD