Security Vulnerabilities
NLTK before 3.10.3 contains an uncontrolled recursion vulnerability in nltk.featstruct.FeatStructReader that allows unauthenticated attackers to cause a denial of service by supplying deeply nested feature-structure input. Attackers can craft trivial payloads with nested brackets that exceed Python's recursion limit and raise an unhandled RecursionError, crashing applications that parse user-supplied feature structures or feature grammars.
CVSS Score
6.9
EPSS Score
0.003
Published
2026-08-27
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, PerceptronTagger, and maxent parameter APIs when pathsec is enabled.
CVSS Score
8.3
EPSS Score
0.003
Published
2026-08-27
NLTK versions before 3.10.3 contain a filesystem containment bypass vulnerability in the Downloader.download and Downloader.incr_download methods that allows attackers to overwrite files outside the install root through pre-existing hardlinks. Attackers with write access to a shared downloader directory can create hardlinks pointing to outside-root files that are then overwritten during normal package extraction, mutating files outside the intended install tree.
CVSS Score
6.9
EPSS Score
0.001
Published
2026-08-27
NLTK before 3.10.3 contains a regular expression denial of service vulnerability in Pl196xCorpusReader that allows attackers to cause quadratic CPU consumption by supplying malformed TEI blocks with many unmatched opening tags. Attackers can exploit lazy regex patterns in the read_block method through public APIs like words() and tagged_words() to force repeated rescans and achieve near-quadratic runtime growth.
CVSS Score
6.3
EPSS Score
0.002
Published
2026-08-27
nltk PorterStemmer in versions <= 3.10.2 (fixed in 3.10.3) contains an inefficient-algorithmic-complexity denial of service in PorterStemmer.stem(). The _is_consonant() helper walks backward over the entire run of trailing 'y' characters on every call, and _measure() invokes it for each stem position, causing O(n^2) behavior. A single ~20-50 KB untrusted token consisting of a long run of the letter 'y' followed by a matching suffix (e.g., 'ness') can pin a CPU core for seconds to minutes, causing availability impact.
CVSS Score
8.7
EPSS Score
0.003
Published
2026-08-27
openssl_encrypt (pip package openssl-encrypt) before 1.4.9 contains two weaknesses in the portable USB drive feature, whose threat model treats the removable drive as untrusted (attacker with physical write access). USBDriveCreator._verify_integrity_file only validates files listed in the manifest, so files added to the drive — including a root-level autorun payload — are not detected and integrity verification still passes. Additionally, a globally constant, source-embedded KDF salt (_LEGACY_FIXED_SALT) is used to derive the drive encryption key for any drive lacking a per-drive salt file, defeating precomputation resistance and enabling an offline rainbow-table attack.
CVSS Score
9.3
EPSS Score
0.001
Published
2026-08-27
openssl_encrypt before 1.4.9 executes untrusted third-party plugins with insufficient controls: the plugin signature policy defaulted to WARN, so an unsigned/unverifiable non-built-in plugin was compiled and executed in the host process at import time, before the runtime sandbox is installed. The only default gate was an incomplete, bypassable AST denylist. If a user is induced to load an attacker's plugin, this results in arbitrary code execution with the privileges of the user running openssl_encrypt. Fixed in 1.4.9 by defaulting the signature policy to ENFORCE for non-built-in plugins.
CVSS Score
9.3
EPSS Score
0.003
Published
2026-08-27
openssl_encrypt before 1.4.9 fails to validate KDF cost parameters in encrypted file metadata and keystore headers, allowing attackers to trigger unbounded memory allocation. Attackers can craft malicious encrypted files declaring arbitrarily large Argon2, scrypt, or balloon KDF parameters to exhaust system memory and crash the process without authentication.
CVSS Score
8.7
EPSS Score
0.004
Published
2026-08-27
openssl-encrypt before 1.4.9 fails to redact the file password in its --debug argv dump when the password is supplied via bundled short-option spellings (e.g. -apHunter2) or abbreviated long-option spellings (e.g. --passw). The sanitizer only recognized exact option names, --option=value forms, and tokens starting with -p, so these spellings bypass the redaction chokepoint and the cleartext password is written to stderr. Anyone with access to that output (terminal scrollback, merged 2>&1 output, CI job logs, or the GUI's persistent debug log) can recover the password.
CVSS Score
8.7
EPSS Score
0.003
Published
2026-08-27
openssl_encrypt before 1.4.9 fails to prevent namespace collisions between own identities and contacts in IdentityStore, allowing attackers to create shadowed contact entries invisible until the corresponding own identity is deleted. When the own identity is deleted, the shadowed contact becomes visible and resolves to the attacker's keys, enabling silent key substitution for encrypted files.
CVSS Score
9.3
EPSS Score
0.001
Published
2026-08-27