Alex Gaynor

10 exploits Active since Mar 2017
CVE-2018-7750 WRITEUP CRITICAL WRITEUP
Paramiko <2.4.1 - RCE
transport.py in the SSH server implementation of Paramiko before 1.17.6, 1.18.x before 1.18.5, 2.0.x before 2.0.8, 2.1.x before 2.1.5, 2.2.x before 2.2.3, 2.3.x before 2.3.2, and 2.4.x before 2.4.1 does not properly check whether authentication is completed before processing other requests, as demonstrated by channel-open. A customized SSH client can simply skip the authentication step.
CVSS 9.8
CVE-2025-3416 WRITEUP LOW WRITEUP
Red Hat Directory Server 11 - Use-After-Free in OpenSSL Properties Handling
A flaw was found in OpenSSL's handling of the properties argument in certain functions. This vulnerability can allow use-after-free exploitation, which may result in undefined behavior or incorrect property parsing, leading to OpenSSL treating the input as an empty string.
CVSS 3.7
CVE-2026-41898 WRITEUP CRITICAL WRITEUP
rust-openssl 0.9.24-0.10.77 - Buffer Overflow
rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.9.24 to before 0.10.78, the FFI trampolines behind SslContextBuilder::set_psk_client_callback, set_psk_server_callback, set_cookie_generate_cb, and set_stateless_cookie_generate_cb forwarded the user closure's returned usize directly to OpenSSL without checking it against the &mut [u8] that was handed to the closure. This can lead to buffer overflows and other unintended consequences. This vulnerability is fixed in 0.10.78.
CVSS 9.8
CVE-2026-28386 WRITEUP HIGH WRITEUP
OpenSSL 3.6.0-3.6.1 - Denial of Service via AES-CFB128 Partial Block Processing
Issue summary: Applications using AES-CFB128 encryption or decryption on systems with AVX-512 and VAES support can trigger an out-of-bounds read of up to 15 bytes when processing partial cipher blocks. Impact summary: This out-of-bounds read may trigger a crash which leads to Denial of Service for an application if the input buffer ends at a memory page boundary and the following page is unmapped. There is no information disclosure as the over-read bytes are not written to output. The vulnerable code path is only reached when processing partial blocks (when a previous call left an incomplete block and the current call provides fewer bytes than needed to complete it). Additionally, the input buffer must be positioned at a page boundary with the following page unmapped. CFB mode is not used in TLS/DTLS protocols, which use CBC, GCM, CCM, or ChaCha20-Poly1305 instead. For these reasons the issue was assessed as Low severity according to our Security Policy. Only x86-64 systems with AVX-512 and VAES instruction support are affected. Other architectures and systems without VAES support use different code paths that are not affected. OpenSSL FIPS module in 3.6 version is affected by this issue.
CVSS 7.5
CVE-2026-27448 WRITEUP MEDIUM WRITEUP
pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback
pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now result in rejecting the connection.
CVSS 5.3
CVE-2026-27459 WRITEUP CRITICAL WRITEUP
pyOpenSSL DTLS cookie callback buffer overflow
pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 22.0.0 and prior to version 26.0.0, if a user provided callback to `set_cookie_generate_callback` returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0.0, cookie values that are too long are now rejected.
CVSS 9.8
CVE-2016-9243 WRITEUP HIGH WRITEUP
cryptography < 1.5.2 - Insufficient Key Length Validation in HKDF
HKDF in cryptography before 1.5.2 returns an empty byte-string if used with a length less than algorithm.digest_size.
CVSS 7.5
CVE-2023-49083 WRITEUP MEDIUM WRITEUP
cryptography 3.1-41.0.5 - Denial of Service via PKCS7 Certificate Deserialization
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Calling `load_pem_pkcs7_certificates` or `load_der_pkcs7_certificates` could lead to a NULL-pointer dereference and segfault. Exploitation of this vulnerability poses a serious risk of Denial of Service (DoS) for any application attempting to deserialize a PKCS7 blob/certificate. The consequences extend to potential disruptions in system availability and stability. This vulnerability has been patched in version 41.0.6.
CVSS 5.9
CVE-2024-26130 WRITEUP HIGH WRITEUP
cryptography 38.0.0-42.0.3 - NULL Pointer Dereference in pkcs12.serialize_key_and_certificates
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Starting in version 38.0.0 and prior to version 42.0.4, if `pkcs12.serialize_key_and_certificates` is called with both a certificate whose public key did not match the provided private key and an `encryption_algorithm` with `hmac_hash` set (via `PrivateFormat.PKCS12.encryption_builder().hmac_hash(...)`, then a NULL pointer dereference would occur, crashing the Python process. This has been resolved in version 42.0.4, the first version in which a `ValueError` is properly raised.
CVSS 7.5
CVE-2026-26007 WRITEUP MEDIUM WRITEUP
cryptography < 46.0.5 - Insufficient Verification of Data Authenticity in Public Key Functions
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 46.0.5, the public_key_from_numbers (or EllipticCurvePublicNumbers.public_key()), EllipticCurvePublicNumbers.public_key(), load_der_public_key() and load_pem_public_key() functions do not verify that the point belongs to the expected prime-order subgroup of the curve. This missing validation allows an attacker to provide a public key point P from a small-order subgroup. This can lead to security issues in various situations, such as the most commonly used signature verification (ECDSA) and shared key negotiation (ECDH). When the victim computes the shared secret as S = [victim_private_key]P via ECDH, this leaks information about victim_private_key mod (small_subgroup_order). For curves with cofactor > 1, this reveals the least significant bits of the private key. When these weak public keys are used in ECDSA , it's easy to forge signatures on the small subgroup. Only SECT curves are impacted by this. This vulnerability is fixed in 46.0.5.
CVSS 6.5