Gnutls vulnerabilities, page 4
74 vulnerabilities
Known vulnerabilities in Gnutls, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.
CVE-2009-5138gnugnutls
EPSS score1.80%
GnuTLS before 2.7.6, when the GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT flag is not enabled, treats version 1 X.509 certificates as intermediate CAs, which allows remote attackers to bypass intended restrictions by leveraging a X.509 V1 certificate from a trusted CA to issue new certificates, a different vulnerability than CVE-2014-1959.CVE-2009-3555apachehttp_server+32EPSS score87.26%
The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft Internet Information Services (IIS) 7.0, mod_ssl in the Apache HTTP Server 2.2.14 and earlier, OpenSSL before 0.9.8l, GnuTLS 2.8.5 and earlier, Mozilla Network Security Services (NSS) 3.12.4 and earlier, multiple Cisco products, and other products, does not properly associate renegotiation handshakes with an existing connection, which allows man-in-the-middle attackers to insert data into HTTPS sessions, and possibly other types of sessions protected by TLS or SSL, by sending an unauthenticated request that is processed retroactively by a server in a post-renegotiation context, related to a "plaintext injection" attack, aka the "Project Mogul" issue.CVE-2019-3836alpinegnutls+7EPSS score3.40%
It was discovered in gnutls before version 3.6.7 upstream that there is an uninitialized pointer access in gnutls versions 3.6.3 or later which can be triggered by certain post-handshake messages.CVE-2019-3829alpinegnutls+8EPSS score58.97%
A vulnerability was found in gnutls versions from 3.5.8 before 3.6.7. A memory corruption (double free) vulnerability in the certificate verification API. Any client or server application that verifies X.509 certificates with GnuTLS 3.5.8 or later is affected.CVE-2026-1584alpinegnutls+4EPSS score1.32%
A flaw was found in gnutls. A remote, unauthenticated attacker can exploit this vulnerability by sending a specially crafted ClientHello message with an invalid Pre-Shared Key (PSK) binder value during the TLS handshake. This can lead to a NULL pointer dereference, causing the server to crash and resulting in a remote Denial of Service (DoS) condition.CVE-2026-42009alpinegnutls+16EPSS score1.13%
A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This could lead to unstable packet ordering or undefined behavior, resulting in a denial of service.CVE-2026-42010alpinegnutls+6EPSS score0.94%
A flaw was found in gnutls. Servers configured with RSA-PSK (Rivest–Shamir–Adleman – Pre-Shared Key) wrongfully matched usernames containing a NUL character with truncated usernames. A remote attacker could exploit this by sending a specially crafted username, leading to an authentication bypass. This vulnerability allows an attacker to gain unauthorized access by circumventing the authentication process.CVE-2026-3833alpinegnutls+6EPSS score0.89%
A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of `nameConstraints` labels, specifically for `dNSName` (DNS) or `rfc822Name` (email) constraints within `excludedSubtrees` or `permittedSubtrees`. A remote attacker can exploit this by crafting a leaf certificate with casing differences in the Subject Alternative Name (SAN), leading to a policy bypass where a certificate that should be rejected is instead accepted. This could result in unauthorized access or information disclosure.CVE-2026-3832alpinegnutls+6EPSS score0.93%
A flaw was found in gnutls. A remote attacker could exploit this vulnerability by presenting a specially crafted Online Certificate Status Protocol (OCSP) response during a TLS handshake. Due to a logic error in how gnutls processes multi-record OCSP responses, a client with OCSP verification enabled may incorrectly accept a revoked server certificate, potentially leading to a compromise of trust.CVE-2026-33845alpinegnutls+5EPSS score0.89%
A flaw in GnuTLS DTLS handshake parsing allows malformed fragments with zero length and non-zero offset, leading to an integer underflow during reassembly and resulting in an out-of-bounds read. This issue is remotely exploitable and may cause information disclosure or denial of service.CVE-2023-0361alpinegnutls+26EPSS score1.45%
A timing side-channel in the handling of RSA ClientKeyExchange messages was discovered in GnuTLS. This side-channel can be sufficient to recover the key encrypted in the RSA ciphertext across a network in a Bleichenbacher style attack. To achieve a successful decryption the attacker would need to send a large amount of specially crafted messages to the vulnerable server. By recovering the secret from the ClientKeyExchange message, the attacker would be able to decrypt the application data exchanged over that connection.CVE-2023-5981alpinegnutls+35EPSS score1.27%
A vulnerability was found that the response times to malformed ciphertexts in RSA-PSK ClientKeyExchange differ from response times of ciphertexts with correct PKCS#1 v1.5 padding.CVE-2006-4790debiangnutls11+4EPSS score2.56%
verify.c in GnuTLS before 1.4.4, when using an RSA key with exponent 3, does not properly handle excess data in the digestAlgorithm.parameters field when generating a hash, which allows remote attackers to forge a PKCS #1 v1.5 signature that is signed by that RSA key and prevents GnuTLS from correctly verifying X.509 and other certificates that use PKCS, a variant of CVE-2006-4339.CVE-2006-7239gnugnutls+4EPSS score1.54%
The _gnutls_x509_oid2mac_algorithm function in lib/gnutls_algorithms.c in GnuTLS before 1.4.2 allows remote attackers to cause a denial of service (crash) via a crafted X.509 certificate that uses a hash algorithm that is not supported by GnuTLS, which triggers a NULL pointer dereference.