NLTK: Corpus Reader Sandbox Bypass

Summary 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. Affected...

GHSA-3GQ4-3J92-5W49 NLTK: Corpus Reader Sandbox Bypass

Summary 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. Affected...

NLTK: Corpus readers follow symlinks outside trusted roots despite pathsec enforcement

Summary Several corpus readers still step outside NLTK's symlink-aware trusted-root model. They derive in-root paths from trusted corpus state, convert those paths back into plain strings, and reopen them with built-in open rather than nltk.pathsec.open. Details - Vulnerability type: Path travers...

GHSA-P4RW-RVV2-7XWR NLTK: Corpus readers follow symlinks outside trusted roots despite pathsec enforcement

Summary Several corpus readers still step outside NLTK's symlink-aware trusted-root model. They derive in-root paths from trusted corpus state, convert those paths back into plain strings, and reopen them with built-in open rather than nltk.pathsec.open. Details - Vulnerability type: Path travers...

EUVD-2026-65526

NLTK: Corpus readers follow symlinks outside trusted roots despite pathsec enforcement...

GHSA-6WW7-3FRV-CQXH NLTK: pathsec SSRF protection can be bypassed when a proxy is configured

Summary Current NLTK source reopens SSRF in proxied environments. pathsec.urlopen validates the requested hostname locally, but once proxy inheritance is enabled the real fetch is performed by the proxy rather than by the validated direct-connect socket path. Details - Vulnerability type:...

NLTK: pathsec SSRF protection can be bypassed when a proxy is configured

Summary Current NLTK source reopens SSRF in proxied environments. pathsec.urlopen validates the requested hostname locally, but once proxy inheritance is enabled the real fetch is performed by the proxy rather than by the validated direct-connect socket path. Details - Vulnerability type:...

GHSA-3HHW-38PF-PXJ6 NLTK: Symlink-based arbitrary file read in IPIPANCorpusReader, bypasses nltk.pathsec entirely

Summary IPIPANCorpusReader nltk/corpus/reader/ipipan.py exposes public methods, channels, domains, categories, and fileidschannels=..., that accept a caller supplied fileids list and read a file via a completely unprotected builtin open call, with no nltk.pathsec involvement at all. A symlink...

EUVD-2026-64339

NLTK: Symlink-based arbitrary file read in IPIPANCorpusReader, bypasses nltk.pathsec entirely...

EUVD-2026-64333

NLTK: StreamBackedCorpusView Bypasses pathsec.ENFORCE - Arbitrary Local File Read...

NLTK: StreamBackedCorpusView Bypasses pathsec.ENFORCE - Arbitrary Local File Read

Summary Setting nltk.pathsec.ENFORCE = True is documented to sandbox all file access to allowed NLTK data directories and raise PermissionError on unauthorized access. However, StreamBackedCorpusView opens files via builtins.open directly, bypassing pathsec.validatepath entirely. An attacker who...

GHSA-X5PH-MJ9P-RFR8 NLTK: StreamBackedCorpusView Bypasses pathsec.ENFORCE - Arbitrary Local File Read

Summary Setting nltk.pathsec.ENFORCE = True is documented to sandbox all file access to allowed NLTK data directories and raise PermissionError on unauthorized access. However, StreamBackedCorpusView opens files via builtins.open directly, bypassing pathsec.validatepath entirely. An attacker who...

SUSE CVE-2026-81726

NLTK through 3.10.3 contains a path traversal vulnerability in model-artifact APIs that bypass pathsec enforcement by using raw file operations on caller-controlled paths. Attackers can read or write files outside allowed sandbox roots through TransitionParser, AveragedPerceptron, PerceptronTagge...

NLTK: Default ENFORCE=False Disables All pathsec Security Controls

NLTK's pathsec.py security module defaults to ENFORCE=False line 24, which means all 8 security validation functions only emit RuntimeWarning instead of raising exceptions when violations are detected. The pathsec module was introduced as the fix for CVE-2024-39705 arbitrary code execution via...

GHSA-P3M8-78J2-G5P3 NLTK: Default ENFORCE=False Disables All pathsec Security Controls

NLTK's pathsec.py security module defaults to ENFORCE=False line 24, which means all 8 security validation functions only emit RuntimeWarning instead of raising exceptions when violations are detected. The pathsec module was introduced as the fix for CVE-2024-39705 arbitrary code execution via...

EUVD-2026-67076

NLTK: Model-artifact APIs bypass pathsec and touch files outside allowed roots...

NLTK: Model-artifact APIs bypass pathsec and touch files outside allowed roots

Summary Several model-artifact APIs still treat caller-controlled model paths as ordinary filenames even when NLTK path security is enforced. The same outside-root paths are rejected by guarded helpers, but these public read and write flows still use raw file APIs. Details - Vulnerability type:...

GHSA-8MGP-746C-J5XP NLTK: Model-artifact APIs bypass pathsec and touch files outside allowed roots

Summary Several model-artifact APIs still treat caller-controlled model paths as ordinary filenames even when NLTK path security is enforced. The same outside-root paths are rejected by guarded helpers, but these public read and write flows still use raw file APIs. Details - Vulnerability type:...

CVE-2026-63312

A flaw was found in NLTK. This vulnerability, specifically within the StreamBackedCorpusView component, allows an attacker to bypass security enforcement by directly calling builtins.open instead of the intended pathsec.open. By controlling the fileid argument, an attacker can read arbitrary loca...

Duplicate Advisory: Model-artifact APIs bypass pathsec and touch files outside allowed roots

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-8mgp-746c-j5xp. This link is maintained to preserve external references. Original Description NLTK through 3.10.3 contains a path traversal vulnerability in model-artifact APIs that bypass pathsec enforcement by...