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Fencer Intel
medium 6.8

CVE-2026-126295 json

NLTK 3.10.0 before 3.10.4 Arbitrary File Read via BllipParser Model Paths

published 20d ago modified yesterday also EUVD-2026-125226 , GHSA-fg9w-wfp5-j933

cvss
6.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits
0
none known

Summary

NLTK from 3.10.0 before 3.10.4 contains an arbitrary file read vulnerability in BllipParser that allows attackers to open files outside NLTK data roots by supplying unvalidated model paths. Attackers controlling parser_model, reranker_features, reranker_weights, or from_unified_model_dir() input can make the bllipparser C extension read sensitive files or block on FIFOs and devices.

Patch / fix

  • pypi nltk 3.10.4
  • nltk nltk 3.10.4

Is CVE-2026-126295 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
yesterday

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-14).

Exploits and checks

  • github.com https://github.com/nltk/nltk/security/advisories/GHSA-fg9w-wfp5-j933 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 7.0 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N
CNA 3.1 6.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L
GitHub 3.1 6.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L
CNA 4.0 7.0 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
pypi nltk
>=3.10.0, <3.10.4
3.10.4

Affected products

  • nltk nltk

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-73 External Control of File Name or Path

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of nltk/nltk published their own advisory on GitHub. Reviewed sources take precedence over it.