Rejetto HFS versions 3.0.0 through 3.2.0 use a cryptographically weak pseudo-random number generator (Math.random()) to derive session-cookie signing keys and disclose outputs of this generator to unauthenticated clients during login. This weakness allows a remote attacker to reconstruct the generator's state, recover the signing key, and forge valid administrator session cookies. Successful exploitation leads to full administrative access and remote code execution via the server_code configuration feature.
Use of a cryptographically weak random number generator in the GenerateRandomPassword function in bosh-windows-stemcell-builder allows a remote attacker to brute-force the resulting SSH login via TCP/22.
Affected versions: bosh-windows-stemcell-builder versions prior to v2019.98.
The DoLogin Security plugin for WordPress is vulnerable to Authentication Bypass via Insufficient Randomness in all versions up to, and including, 4.3. The vulnerability exists because `dologin\s::rrand()` seeds the Mersenne Twister with `mt_srand((double) microtime() * 1000000)` — discarding the integer-seconds component of `microtime()` and constraining the seed to a range of approximately 10^6 values (~20 bits of entropy) — after which every character of the 32-character magic-link token is drawn sequentially with `mt_rand()`, making the entire token a deterministic function of that seed. Because `Pswdless::try_login()` is registered on the unauthenticated `init` hook, resolves the target account by the auto-increment numeric ID embedded in the `?dologin=<id>.<hash>` parameter, performs the hash comparison using a non-constant-time `!=` operator, and then calls `wp_set_auth_cookie()` directly — never passing through `wp_authenticate()` and therefore never triggering the plugin's own `Auth::_has_login_err()` lockout — an unauthenticated attacker can brute-force the ~10^6-candidate seed space to reconstruct an active passwordless login token and authenticate as any targeted user, including administrators, without a password. Exploitation requires that a valid, unexpired passwordless login link (active for up to 7 days) exists for the target account at the time of the attack, and that the numeric link ID is known or guessable from the auto-increment primary key.
CGI::Session::ID::md5 versions before 4.49 for Perl generate predictable session ids from low-entropy sources.
The generate_id method builds the session id from a MD5 digest of the process id, the epoch time, and the built-in rand() function. All three are predictable, low-entropy sources: the PID is drawn from a small range, the epoch time can be guessed or read from the HTTP Date header, and Perl's rand() is unsuitable for security purposes because it is predictable and reversible.
An attacker who predicts a session id can impersonate the corresponding session and bypass authentication.
UltraVNC through 1.8.2.2 uses inadequate cryptography in the MS-Logon II authentication scheme (rfbUltraVNC_MsLogonIIAuth). In rfb/dh.cpp the Diffie-Hellman key exchange is performed with parameters that fit in an unsigned 64-bit integer (DH_MAX_BITS controls the prime size). A 64-bit DH key can be broken by Pollard's rho algorithm in under one second on current hardware. Additionally, the private exponent is generated by the rng() function, which multiplies three libc rand() values seeded from time(NULL). With approximately 31 bits of internal state and a time-based seed, the private exponent is recoverable in under a minute by a passive observer. A network attacker who can observe the MS-Logon II handshake (via sniffing, recording, or man-in-the-middle) can derive the shared DH key and decrypt the encapsulated username and password, resulting in full credential disclosure. This affects legacy MS-Logon II connections; MS-Logon III (X25519 + AES-256-GCM) is unaffected.
UltraVNC through 1.8.2.2 uses a cryptographically weak pseudo-random number generator to produce VNC authentication challenge bytes. In rfb/vncauth.c:119-129, the vncRandomBytes() function seeds libc rand() with time(0) + getpid() + rand() and generates a 16-byte challenge. The combined seed space is approximately 31 bits (libc rand() internal state) and is entirely determined by publicly-observable values (wall-clock time and process ID). An attacker who can observe the authentication exchange can enumerate the seed space and predict the challenge within seconds, enabling forgery or offline brute-forcing of responses. Note: on Windows, the active code path may use vncEncryptBytes2.cpp which calls CryptGenRandom; reachability on shipped Windows binaries requires compile-graph verification and is under investigation.
IBM Langflow OSS 1.0.0 through 1.10.0 Langflow could allow disclosure of all stored credentials due to the use of a weak and reversible key derivation mechanism for encryption at rest.
Net::BitTorrent versions before 2.1.0 for Perl generate the MSE Diffie-Hellman private key with a non-cryptographic PRNG.
The MSE (Message Stream Encryption) handshake derives its 160-bit Diffie-Hellman private key from Perl's rand(), a non-cryptographic drand48-class generator seeded once per process, in KeyExchange.pm. The shared secret and the RC4 keys derived from it (the SHA-1 of "keyA" or "keyB", the shared secret, and the infohash) therefore depend entirely on a predictable PRNG. The same handshake sends, in cleartext, random padding drawn from the same rand() sequence in _random_pad, immediately after the public key and the private-key draw.
A passive observer of the handshake recovers the PRNG state from the cleartext padding, reconstructs the private key, computes the shared secret from the peer's public key on the wire, derives the RC4 keys, and decrypts the connection, defeating the passive-observation obfuscation MSE provides.
Mojolicious::Plugin::Web::Auth::OAuth2 versions through 0.17 for Perl have an insecure default state parameter.
When no state generator is specified in the constructor, the module defaults to using a SHA-1 hash of predictable and low-entropy sources, including the epoch time (which is leaked via the HTTP Date header) and a call to Perl's built-in rand function.
A predictable state allows an attacker to hijack another user's session through cross site request forgery (CSRF).
In JetBrains Hub before 2026.1.13757,
2025.3.148033,
2025.2.148048,
2025.1.148120,
2024.3.148430,
2024.2.148429 account takeover via predictable restore codes was possible
Mojolicious::Sessions::Storable versions through 0.05 for Perl generate session ids insecurely.
The default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, the heap address of an anonymous hash, and the PID.
These are predictable or low-entropy sources that are unsuitable for security purposes.
Dancer2::Plugin::Auth::OAuth versions before 0.22 for Perl use a predictable nonce generated by hashing the epoch time with MD5, which is a cryptographically weak pseudo-random number generator. This vulnerability (CVE-2026-11832) can lead to compromised confidentiality and integrity of authentication tokens. The CVSS score is 9.1, indicating a critical severity level. No official patch or remediation guidance is currently provided by the vendor.
Crypt::PBKDF2 versions before 0.261630 for Perl use a cryptographically weak pseudo-random number generator for salt generation. Specifically, these versions rely on the built-in rand function, which is predictable and unsuitable for cryptographic purposes. This weakness can compromise the security of derived keys by making salts guessable.
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Versions prior to 26.0.1 use `uniqid` for generating salts, which is unsuitable. Version 26.0.1 fixes the issue.
The linqi application contains hardcoded cryptographic keys. Additionally, the application uses a weak algorithm with a limited ASCII charset to dynamically generate Initialization Vectors (IVs) for AES/CBC encryption, making known-plaintext attacks feasible. An attacker with local access can leverage these vulnerabilities to decrypt sensitive obfuscated strings, including ConnectionString values containing database credentials from appsettings.json.
Weak Randomness / Insecure Cryptographic Primitive (CWE-338) in Get-RandomPassword in BOSH-Ecosystem / windows-utilities-release allows a network attacker to estimate VM boot time and reconstruct a small candidate list to recover the Administrator password. The randomize_password job exists solely to lock the local Administrator account behind an unguessable password as a hardening control. Because the password is derived from a predictable, clock-seeded PRNG, a network attacker who can estimate VM boot time can reconstruct a small candidate list and recover the Administrator password, defeating the hardening control.
Affected versions:
- windows-utilities-release: all versions prior to v0.23.0 (inclusive); fixed in v0.23.0 or later
CVE-2026-8647 is a medium severity vulnerability in the Perl module Crypt::ScryptKDF versions through 0.010. The module uses an insecure random number source when no cryptographically secure pseudo-random number generator (CSPRNG) module is available. Specifically, the random_bytes function falls back to the built-in rand() function, which is not cryptographically secure. This weakness can reduce the effectiveness of cryptographic operations relying on this module.
Crypt::SaltedHash versions through 0.09 for Perl generate insecure random values for salts.
These versions use the built-in rand function, which is predictable and unsuitable for cryptography.
Magento Long Term Support (LTS) is an unofficial, community-driven project provides an alternative to the Magento Community Edition e-commerce platform with a high level of backward compatibility. Prior to 20.18.0, the XML-RPC / SOAP API session ID is generated using an outdated, time-based construction rather than a Cryptographically Secure Pseudo-Random Number Generator (CSPRNG). All inputs to the MD5 hash are time-derived and non-secure. Because the resulting digest relies entirely on the timestamp and the PHP internal LCG state, the effective entropy is severely constrained. This violates the OWASP ASVS v4 requirement of ≥ 64 bits of entropy (V3.2.2) and NIST SP 800-63B standards. By narrowing the LCG window (via server state leaks or general predictability) and leveraging the lack of API rate-limiting, an attacker can generate a localized pool of candidate MD5 hashes and execute a high-speed online brute-force attack to hijack active API sessions. This vulnerability is fixed in 20.18.0.
CVE-2026-8503 is a medium severity vulnerability in Apache::Session::Generate::SHA256 versions before 1.3.19 for Perl. The module generates session IDs using predictable, low-entropy sources such as the built-in rand() function, epoch time, and process ID, which are hashed with SHA-256. This predictability can allow attackers to guess session IDs and potentially gain unauthorized access. Version 1.3.19 includes a fallback to an insecure method only if Crypt::URandom::urandom fails, which is unlikely since Crypt::URandom is a required dependency. No official patch or remediation guidance is currently available.