Staging Environment: Content and features may be unstable or change without notice.
Advisory details: gitlab / pypi/nltk/CVE-2026-79674
Advisory ID gitlab/pypi/nltk/CVE-2026-79674
Aliases CVE-2026-79674
GHSA-3gq4-3j92-5w49
Summary NLTK: Corpus Reader Sandbox Bypass NLTK corpus-reader constructors can still reach outside-root file and database reads before the `nltk.pathsec` sandbox boundary is enforced. The PoC shows the safe path blocked by `pathsec.open`, then `LinThesaurusCorpusReader` and `PanLexLiteCorpusReader` succeeding in the same process.
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (3)
CWE-73 External Control of File Name or Path
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv3.1 https://gitlab.com/gitlab-org/advisories-community/-/blob/main/pypi/nltk/CVE-2026-79674.yml
Reference id Reference type URL
https://github.com/nltk/nltk/commit/bc007200d123c1a98d74c2eb230f5e06c53886b8
https://github.com/nltk/nltk/releases/tag/v3.10.3
https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-3736.yaml
CVE-2026-79674 https://nvd.nist.gov/vuln/detail/CVE-2026-79674
GHSA-3gq4-3j92-5w49 https://github.com/advisories/GHSA-3gq4-3j92-5w49
GHSA-3gq4-3j92-5w49 Advisory https://github.com/nltk/nltk/security/advisories/GHSA-3gq4-3j92-5w49
nltk-path-traversal-via-corpus-reader-constructors Advisory https://www.vulncheck.com/advisories/nltk-path-traversal-via-corpus-reader-constructors
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N Found at https://gitlab.com/gitlab-org/advisories-community/-/blob/main/pypi/nltk/CVE-2026-79674.yml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

There are no SSVC decisions available.