GnuTLS vulnerabilities

Summary

It was discovered that GnuTLS had a timing side-channel when processing malformed ciphertexts in RSA-PSK ClientKeyExchange. A remote attacker could possibly use this issue to recover sensitive information. This issue only affected Ubuntu 18.04 LTS. (CVE-2024-0553) Bing Shi discovered that GnuTLS incorrectly handled decoding certain DER-encoded certificates. A remote attacker could possibly use this issue to cause GnuTLS to consume resources, leading to a denial of service. This issue only affected Ubuntu 18.04 LTS. (CVE-2024-12243) Luigino Camastra discovered that GnuTLS incorrectly handled certain PKCS11 token labels. A remote attacker could use this issue to cause GnuTLS to crash, resulting in a denial of service, or possibly execute arbitrary code. The default compiler options for affected releases should reduce the vulnerability to a denial of service. (CVE-2025-9820) Tim Scheckenbach discovered that GnuTLS incorrectly handled malicious certificates containing a large number of name constraints and subject alternative names. A remote attacker could possibly use this issue to cause GnuTLS to consume resources, resulting in a denial of service. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2025-14831) Oleh Konko and Joshua Rogers discovered that GnuTLS did not properly handle case-insensitive name constraints in certain cases. A remote attacker could po Affected Ubuntu releases: 20.04, 18.04, 16.04. CVEs: CVE-2026-33846, CVE-2026-3833, CVE-2026-42009, CVE-2026-5260, CVE-2026-33845, CVE-2024-12243, CVE-2025-14831, CVE-2025-9820….