CVE-2026-81726Public exploitNetwork attack vector

Arbitrary file access via unguarded model paths

Published Aug 27, 2026 · Updated Aug 27, 2026

Path traversal in NLTK 3.10.3 and earlier allows remote attackers to read or write files outside pathsec sandbox roots. Model helpers in TransitionParser, AveragedPerceptron, PerceptronTagger, and maxent pass caller-controlled paths to raw file APIs instead of guarded helpers. Exploitation requires pathsec enforcement and an application that exposes a vulnerable model-path argument; access remains bounded by the host process.

CVSS severity7.0
High
EPSS probability0.26%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Path traversal in NLTK 3.10.3 and earlier allows remote attackers to read or write files outside pathsec sandbox roots. Model helpers in TransitionParser, AveragedPerceptron, PerceptronTagger, and maxent pass caller-controlled paths to raw file APIs instead of guarded helpers. Exploitation requires pathsec enforcement and an application that exposes a vulnerable model-path argument; access remains bounded by the host process.

The record

CVE
CVE-2026-81726
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
NLTK Project
Product
NLTK
Classifications
CWE-22, CWE-73, CWE-59, T1005, T1565.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=3.10.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

NLTK Project · NLTKversion=0 <=3.10.3

Published CVSS scores

7.0NLTK ProjectCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-73External Control of File Name or Path
CWE-59Improper Link Resolution Before File Access ('Link Following')
T1005Data from Local System
T1565.001Stored Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo