Critical GnuTLS Vulnerabilities Affecting Ubuntu Systems

Multiple vulnerabilities in GnuTLS have been identified, primarily affecting Ubuntu 18.04 LTS and 20.04 LTS. A timing side-channel vulnerability (CVE-2024-0553) could allow remote attackers to recover sensitive information. Additionally, issues with DER-encoded certificates (CVE-2024-12243) and PKCS11 token labels (CVE-2025-9820) could lead to denial of service or arbitrary code execution. The vulnerabilities were discovered by researchers including Bing Shi and Luigino Camastra. The affected systems are primarily Ubuntu 18.04 LTS, with some issues also impacting Ubuntu 20.04 LTS. Users are advised to update their systems to mitigate these risks. The vulnerabilities were disclosed in security advisories published on July 6, 2026.

Key Points: • GnuTLS vulnerabilities could lead to information disclosure and denial of service. • Affected systems include Ubuntu 18.04 LTS and 20.04 LTS. • Immediate updates are recommended to mitigate the identified risks.