CVE-2026-63312

HIGH 7.5

NLTK StreamBackedCorpusView Bypasses pathsec.ENFORCE Arbitrary File Read

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open() directly instead of pathsec.open(). Attackers who control the fileid argument can read arbitrary local files regardless of the ENFORCE setting, including sensitive system files and application credentials.

CWE	CWE-22
Vendor	nltk
Product	nltk
Published	Aug 22, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Affected Versions

nltk / nltk

0 < 3.10.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/nltk/nltk/security/advisories/GHSA-x5ph-mj9p-rfr8 vulncheck.com: https://www.vulncheck.com/advisories/nltk-streambackedcorpusview-bypasses-pathsec-enforce-arbitrary-file-read

Credits

🔍 meme-dm