Regular Expression Denial of Service (ReDoS)

Overview nltk is a Natural Language Toolkit NLTK is a Python package for natural language processing. Affected versions of this package are vulnerable to Regular Expression Denial of Service ReDoS in TokenSearcher.findall and Text.findall in nltk/text.py. An attacker can pin a Python worker and...

Regular Expression Denial of Service (ReDoS)

Overview nltk is a Natural Language Toolkit NLTK is a Python package for natural language processing. Affected versions of this package are vulnerable to Regular Expression Denial of Service ReDoS through the tgrepnodeaction path in nltk/tgrep.py. An attacker can pin a CPU core indefinitely by...

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-2026-80205

NLTK versions before 3.10.0 contain a regular expression denial of service vulnerability in Text.findall and TokenSearcher.findall methods that accept user-supplied regular expressions without validation or timeout. Attackers can supply crafted regex patterns that cause catastrophic backtracking,...

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...

UBUNTU-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 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-2026-80205 NLTK before 3.10.0 ReDoS via Text.findall() unvalidated regex

NLTK versions before 3.10.0 contain a regular expression denial of service vulnerability in Text.findall and TokenSearcher.findall methods that accept user-supplied regular expressions without validation or timeout. Attackers can supply crafted regex patterns that cause catastrophic backtracking,...

CVE-2026-80205 NLTK before 3.10.0 ReDoS via Text.findall() unvalidated regex

NLTK versions before 3.10.0 contain a regular expression denial of service vulnerability in Text.findall and TokenSearcher.findall methods that accept user-supplied regular expressions without validation or timeout. Attackers can supply crafted regex patterns that cause catastrophic backtracking,...

CVE-2026-80205

NLTK versions before 3.10.0 are vulnerable to a ReDoS (Regular Expression Denial of Service) in the Text.findall() and TokenSearcher.findall() methods. These methods accept user-supplied regular expressions without validation or a timeout mechanism, allowing an attacker to supply crafted patterns...

CVE-2026-80205

NLTK versions before 3.10.0 contain a regular expression denial of service vulnerability in Text.findall and TokenSearcher.findall methods that accept user-supplied regular expressions without validation or timeout. Attackers can supply crafted regex patterns that cause catastrophic backtracking,...

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...

Linux Distros Unpatched Vulnerability : CVE-2026-79770

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - Nokogiri versions before 1.19.3 contain regular expression denial of service vulnerabilities in the CSS selector tokenizer affecting string-literal and identifi...

Unity Linux 20.1050e / 20.1060e / 20.1070e Security Update: python-py (UTSA-2026-093196)

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-093196 advisory. A denial of service via regular expression in the py.path.svnwc component of py aka python-py through 1.9.0 could be used by attackers to cause a compute-time denial...

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...