NLTK: ReDoS in nltk.tgrep via unvalidated user-supplied regular expressions

Summary The NLTK tgrep module accepts user-supplied regular expressions and passes them to the Python re engine without a timeout or validation, enabling catastrophic backtracking ReDoS. Applications that expose the tgrep API to external input are vulnerable to a single-request denial of service...

GHSA-W3V8-GMH9-3WV7 NLTK: ReDoS in nltk.tgrep via unvalidated user-supplied regular expressions

Summary The NLTK tgrep module accepts user-supplied regular expressions and passes them to the Python re engine without a timeout or validation, enabling catastrophic backtracking ReDoS. Applications that expose the tgrep API to external input are vulnerable to a single-request denial of service...

EUVD-2026-66397

NLTK: ReDoS in nltk.tgrep via unvalidated user-supplied regular expressions...

Duplicate Advisory: ReDoS in nltk.tgrep via unvalidated user-supplied regular expressions

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-w3v8-gmh9-3wv7. This link is maintained to preserve external references. Original Description NLTK before 3.10.3 contains a regular expression denial of service ReDoS vulnerability in the tgrep module. The...

CVE-2026-80206

A flaw was found in NLTK, specifically within its tgrep module. This vulnerability, known as Regular Expression Denial of Service ReDoS, allows a remote attacker to provide specially crafted regular expressions. When processed, these expressions can cause indefinite CPU saturation, leading to a...

PYSEC-2026-3751

NLTK before 3.10.3 contains a regular expression denial of service ReDoS vulnerability in the tgrep module. The tgrepnodeaction function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or...

PYSEC-2026-3751

NLTK before 3.10.3 contains a regular expression denial of service ReDoS vulnerability in the tgrep module. The tgrepnodeaction function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or...

CVE-2026-80206

NLTK before 3.10.3 contains a regular expression denial of service ReDoS vulnerability in the tgrep module. The tgrepnodeaction function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or...

CVE-2026-80206 NLTK 3.10.2 Regular Expression Denial of Service via tgrep

NLTK before 3.10.3 contains a regular expression denial of service ReDoS vulnerability in the tgrep module. The tgrepnodeaction function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or...

CVE-2026-80206

NLTK (a Python natural language processing library) versions before 3.10.3 contain a ReDoS vulnerability in the tgrep module. The _tgrep_node_action function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels witho...

CVE-2026-80206 NLTK 3.10.2 Regular Expression Denial of Service via tgrep

NLTK before 3.10.3 contains a regular expression denial of service ReDoS vulnerability in the tgrep module. The tgrepnodeaction function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or...

CVE-2026-80206 NLTK 3.10.2 Regular Expression Denial of Service via tgrep

NLTK before 3.10.3 contains a regular expression denial of service ReDoS vulnerability in the tgrep module. The tgrepnodeaction function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or...

CVE-2026-80206: Inefficient Regular Expression Complexity

NLTK before 3.10.3 contains a regular expression denial of service ReDoS vulnerability in the tgrep module. The tgrepnodeaction function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or...

Linux Distros Unpatched Vulnerability : CVE-2026-80206

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - NLTK before 3.10.3 contains a regular expression denial of service ReDoS vulnerability in the tgrep module. The tgrepnodeaction function compiles user-supplied...

PT-2026-82080

Name of the Vulnerable Software and Affected Versions NLTK versions prior to 3.10.3 Description The tgrep module contains a regular expression denial of service ReDoS issue. The tgrep node action function compiles user-supplied regular expressions within /regex/ pattern nodes and executes them...