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 sequen...
Product
gnutls vulnerabilities
74 published CVES affecting gnutls, from public sources (CVE.org, NVD, CISA KEV, FIRST EPSS, OSV).
- Total
- 74
- Critical
- 7
- High
- 30
- Medium
- 36
- Low
- 1
- Unscored
- 0
- CISA KEV
- 0
Latest gnutls CVEs
Newest publication first · page 1 of 3
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HighCVSS 7.5
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CriticalCVSS 9.8
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 authe...
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CriticalCVSS 9.1
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...
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LowCVSS 3.7
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...
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CVE-2026-3833 Gnutls: gnutls: policy bypass due to case-sensitive nameconstraints comparison
PublishedHighCVSS 7.4A 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...
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HighCVSS 7.5
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 se...
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HighCVSS 8.2
A heap-buffer-overflow (off-by-one) flaw was found in the GnuTLS software in the template parsing logic within the certtool utility. When it reads certain settings from a template file, it allows an attacker to cause an out-of-bounds (OOB) NULL pointer write, resulting in memory...
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MediumCVSS 5.3
A heap-buffer-overread vulnerability was found in GnuTLS in how it handles the Certificate Transparency (CT) Signed Certificate Timestamp (SCT) extension during X.509 certificate parsing. This flaw allows a malicious user to create a certificate containing a malformed SCT extensi...
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HighCVSS 8.2
A flaw was found in GnuTLS. A double-free vulnerability exists in GnuTLS due to incorrect ownership handling in the export logic of Subject Alternative Name (SAN) entries containing an otherName. If the type-id OID is invalid or malformed, GnuTLS will call asn1_delete_structure()...
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HighCVSS 7.5
A vulnerability was found in GnuTLS, where a cockpit (which uses gnuTLS) rejects a certificate chain with distributed trust. This issue occurs when validating a certificate chain with cockpit-certificate-ensure. This flaw allows an unauthenticated, remote client or attacker to in...
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HighCVSS 7.5
A vulnerability was found in GnuTLS. The response times to malformed ciphertexts in RSA-PSK ClientKeyExchange differ from the response times of ciphertexts with correct PKCS#1 v1.5 padding. This issue may allow a remote attacker to perform a timing side-channel attack in the RSA-...
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MediumCVSS 5.9
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.
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HighCVSS 7.4
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 attac...
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MediumCVSS 6.5
A NULL pointer dereference flaw was found in GnuTLS. As Nettle's hash update functions internally call memcpy, providing zero-length input may cause undefined behavior. This flaw leads to a denial of service after authentication in rare circumstances.
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HighCVSS 7.5
A vulnerability found in gnutls. This security flaw happens because of a double free error occurs during verification of pkcs7 signatures in gnutls_pkcs7_verify function.
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CriticalCVSS 9.8
A flaw was found in gnutls. A use after free issue in client_send_params in lib/ext/pre_shared_key.c may lead to memory corruption and other potential consequences.
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CriticalCVSS 9.8
A flaw was found in gnutls. A use after free issue in client sending key_share extension may lead to memory corruption and other consequences.
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HighCVSS 7.5
An issue was discovered in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. The crash happens in the application's error handling path...
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HighCVSS 7.4
GnuTLS 3.6.x before 3.6.14 uses incorrect cryptography for encrypting a session ticket (a loss of confidentiality in TLS 1.2, and an authentication bypass in TLS 1.3). The earliest affected version is 3.6.4 (2018-09-24) because of an error in a 2018-09-18 commit. Until the first...
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HighCVSS 7.4
GnuTLS 3.6.x before 3.6.13 uses incorrect cryptography for DTLS. The earliest affected version is 3.6.3 (2018-07-16) because of an error in a 2017-10-06 commit. The DTLS client always uses 32 '\0' bytes instead of a random value, and thus contributes no randomness to a DTLS negot...
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HighCVSS 7.5
GnuTLS before 3.3.13 does not validate that the signature algorithms match when importing a certificate.
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MediumCVSS 5.9
GnuTLS incorrectly validates the first byte of padding in CBC modes
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HighCVSS 7.5
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.
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HighCVSS 7.5
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.
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MediumCVSS 5.6
A Bleichenbacher type side-channel based padding oracle attack was found in the way gnutls handles verification of RSA decrypted PKCS#1 v1.5 data. An attacker who is able to run process on the same physical core as the victim process, could use this to extract plaintext or in som...
Sources: CVE.org, NVD, CISA KEV, FIRST EPSS, OSV and public exploit-reference metadata. Product matching comes from the published CVE records. A proof-of-concept means public code exists; it is not evidence of exploitation.