VDB-376259 · CVE-2026-12252 · EUVD-2026-41656

nltk up to 3.9.3 Stanford Interface code injection

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6.4	$0-$5k	0.00+

Summaryinfo

A vulnerability identified as critical has been detected in nltk up to 3.9.3. This issue affects the function StanfordPOSTagger/StanfordNERTagger/StanfordParser/StanfordDependencyParser/StanfordNeuralDependencyParser of the component Stanford Interface. The manipulation leads to code injection. This vulnerability is traded as CVE-2026-12252. An attack has to be approached locally. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in nltk up to 3.9.3 and classified as critical. This issue affects the function StanfordPOSTagger/StanfordNERTagger/StanfordParser/StanfordDependencyParser/StanfordNeuralDependencyParser of the component Stanford Interface. The manipulation with an unknown input leads to a code injection vulnerability. Using CWE to declare the problem leads to CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In nltk/nltk versions 3.9.3 and earlier, five Stanford interface classes (StanfordPOSTagger, StanfordNERTagger, StanfordParser, StanfordDependencyParser, and StanfordNeuralDependencyParser) are vulnerable to untrusted JAR code execution. These classes accept user-controllable JAR paths and execute them via the `java()` function, which invokes `subprocess.Popen()` without integrity verification. This vulnerability is identical to CVE-2026-0848, which was fixed for StanfordSegmenter by adding SHA256 verification. However, the fix was not applied to these additional classes, leaving them susceptible to arbitrary code execution when loading untrusted JAR files.

It is possible to read the advisory at huntr.com. The identification of this vulnerability is CVE-2026-12252 since 06/15/2026. The exploitation is known to be easy. Attacking locally is a requirement. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1059 according to MITRE ATT&CK.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-41656). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

nltk

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.8
CNA Vector (@huntr_ai): 🔒

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Code injection
CWE: CWE-94 / CWE-74 / CWE-707
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

06/15/2026 CVE reserved
07/04/2026 +19 days Advisory disclosed
07/04/2026 +0 days VulDB entry created
07/04/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: huntr.com
Status: Confirmed

CVE: CVE-2026-12252 (🔒)
GCVE (CVE): GCVE-0-2026-12252
GCVE (VulDB): GCVE-100-376259
EUVD: 🔒

Entryinfo

Created: 07/04/2026 06:16
Updated: 07/04/2026 07:17
Changes: 07/04/2026 06:16 (63), 07/04/2026 07:17 (1)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.