CVE-2026-72818

A flaw was found in NLTK. The TweetTokenizer component, used for processing social media text, contains a regular expression vulnerability. A remote unauthenticated attacker can provide specially crafted input containing many alternating label separators, causing the regular expression to backtra...

Linux Distros Unpatched Vulnerability : CVE-2026-72818

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain bran...

EUVD-2026-63729

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix a-z0-9+?:.-a-z0-9+ is unbounded. Input consisting of many alternating label separators can be partitioned in...

GHSA-QX2G-XRX7-VFH8 NLTK TweetTokenizer vulnerable to denial of service through catastrophic regex backtracking

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix a-z0-9+?:.-a-z0-9+ is unbounded. Input consisting of many alternating label separators can be partitioned in...

CVE-2026-72818

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix a-z0-9+?:.-a-z0-9+ is unbounded. Input consisting of many alternating label separators can be partitioned in...

DEBIAN-CVE-2026-72818

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix a-z0-9+?:.-a-z0-9+ is unbounded. Input consisting of many alternating label separators can be partitioned in...

CVE-2026-72818

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix a-z0-9+?:.-a-z0-9+ is unbounded. Input consisting of many alternating label separators can be partitioned in...

UBUNTU-CVE-2026-72818

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix a-z0-9+?:.-a-z0-9+ is unbounded. Input consisting of many alternating label separators can be partitioned in...

CVE-2026-72818 NLTK TweetTokenizer URL Pattern Backtracks Catastrophically on Naked-Domain-Like Input

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix a-z0-9+?:.-a-z0-9+ is unbounded. Input consisting of many alternating label separators can be partitioned in...

CVE-2026-72818 NLTK TweetTokenizer URL Pattern Backtracks Catastrophically on Naked-Domain-Like Input

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix a-z0-9+?:.-a-z0-9+ is unbounded. Input consisting of many alternating label separators can be partitioned in...

CVE-2026-72818

NLTK (Python NLP library) is vulnerable to catastrophic regex backtracking in nltk/tokenize/casual.py. The TweetTokenizer.WORD_RE pattern contains an unbounded naked-domain label prefix [a-z0-9]+(?:[.\-][a-z0-9]+)*. Crafted input with many alternating label separators causes the regex engine to e...

CVE-2026-72818 NLTK TweetTokenizer URL Pattern Backtracks Catastrophically on Naked-Domain-Like Input

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix a-z0-9+?:.-a-z0-9+ is unbounded. Input consisting of many alternating label separators can be partitioned in...

CVE-2026-72818

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORDRE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix a-z0-9+?:.-a-z0-9+ is unbounded. Input consisting of many alternating label separators can be partitioned in...

PT-2026-79260

Name of the Vulnerable Software and Affected Versions NLTK versions prior to 3.10.1 Description The URLS regular expression in nltk/tokenize/casual.py, which is compiled into TweetTokenizer.WORD RE and used by TweetTokenizer.tokenize, contains an unbounded domain-label prefix. When processing inp...