{"id":"UBUNTU-CVE-2025-9820","details":"A flaw was found in the GnuTLS library, specifically in the gnutls_pkcs11_token_init() function that handles PKCS#11 token initialization. When a token label longer than expected is processed, the function writes past the end of a fixed-size stack buffer. This programming error can cause the application using GnuTLS to crash or, in certain conditions, be exploited for code execution. As a result, systems or applications relying on GnuTLS may be vulnerable to a denial of service or local privilege escalation attacks.","modified":"2026-03-19T10:32:34.601802Z","published":"2026-01-26T20:16:00Z","related":["USN-8043-1"],"upstream":["CVE-2025-9820"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2025-9820"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2025-9820"},{"type":"REPORT","url":"https://www.gnutls.org/security-new.html#GNUTLS-SA-2025-11-18"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8043-1"}],"affected":[{"package":{"name":"gnutls28","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/gnutls28@3.4.10-4ubuntu1.9+esm2?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.15-5ubuntu2","3.3.18-1ubuntu1","3.3.20-1ubuntu1","3.4.9-2ubuntu1","3.4.10-4ubuntu1","3.4.10-4ubuntu1.1","3.4.10-4ubuntu1.2","3.4.10-4ubuntu1.3","3.4.10-4ubuntu1.4","3.4.10-4ubuntu1.5","3.4.10-4ubuntu1.6","3.4.10-4ubuntu1.7","3.4.10-4ubuntu1.8","3.4.10-4ubuntu1.9","3.4.10-4ubuntu1.9+esm1","3.4.10-4ubuntu1.9+esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"3.4.10-4ubuntu1.9+esm2","binary_name":"gnutls-bin"},{"binary_version":"3.4.10-4ubuntu1.9+esm2","binary_name":"guile-gnutls"},{"binary_version":"3.4.10-4ubuntu1.9+esm2","binary_name":"libgnutls-dev"},{"binary_version":"3.4.10-4ubuntu1.9+esm2","binary_name":"libgnutls-openssl27"},{"binary_version":"3.4.10-4ubuntu1.9+esm2","binary_name":"libgnutls28-dev"},{"binary_version":"3.4.10-4ubuntu1.9+esm2","binary_name":"libgnutls30"},{"binary_version":"3.4.10-4ubuntu1.9+esm2","binary_name":"libgnutlsxx28"}],"priority_reason":"GnuTLS developers have rated this to be low 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developers have rated this to be low severity"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-9820.json"}},{"package":{"name":"gnutls28","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/gnutls28@3.6.13-2ubuntu1.12+esm1?arch=source&distro=esm-infra/focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.6.9-5ubuntu1","3.6.9-5ubuntu2","3.6.10-5","3.6.11.1-2","3.6.11.1-2ubuntu2","3.6.13-2ubuntu1","3.6.13-2ubuntu1.1","3.6.13-2ubuntu1.2","3.6.13-2ubuntu1.3","3.6.13-2ubuntu1.6","3.6.13-2ubuntu1.7","3.6.13-2ubuntu1.8","3.6.13-2ubuntu1.9","3.6.13-2ubuntu1.10","3.6.13-2ubuntu1.11","3.6.13-2ubuntu1.12","3.6.13-2ubuntu1.12+esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.6.13-2ubuntu1.12+esm1","binary_name":"gnutls-bin"},{"binary_version":"3.6.13-2ubuntu1.12+esm1","binary_name":"guile-gnutls"},{"binary_version":"3.6.13-2ubuntu1.12+esm1","binary_name":"libgnutls-dane0"},{"binary_version":"3.6.13-2ubuntu1.12+esm1","binary_name":"libgnutls-openssl27"},{"binary_version":"3.6.13-2ubuntu1.12+esm1","binary_name":"libgnutls28-dev"},{"binary_version":"3.6.13-2ubuntu1.12+esm1","binary_name":"libgnutls30"},{"binary_version":"3.6.13-2ubuntu1.12+esm1","binary_name":"libgnutlsxx28"}],"priority_reason":"GnuTLS 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