{"id":"CVE-2025-9820","summary":"Gnutls: stack-based buffer overflow in gnutls_pkcs11_token_init() function","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":"2026-09-03T08:05:35.091830Z","published":"2026-01-26T19:58:32.886Z","related":["ALSA-2026:3477","ALSA-2026:4188","ALSA-2026:5585","SUSE-SU-2025:21202-1","SUSE-SU-2025:21222-1","SUSE-SU-2025:4271-1","SUSE-SU-2025:4272-1","SUSE-SU-2025:4323-1","SUSE-SU-2025:4346-1","SUSE-SU-2025:4525-1","SUSE-SU-2026:20962-1","SUSE-SU-2026:20968-1","SUSE-SU-2026:20984-1","SUSE-SU-2026:2367-1","openSUSE-SU-2025:15765-1","openSUSE-SU-2026:20446-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/9xxx/CVE-2025-9820.json","cna_assigner":"redhat","cwe_ids":["CWE-121"]},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2025/11/20/2"},{"type":"WEB","url":"https://access.redhat.com/downloads/content/package-browser/"},{"type":"WEB","url":"https://catalog.redhat.com/software/containers/"},{"type":"WEB","url":"https://cert-portal.siemens.com/productcert/html/ssa-032379.html"},{"type":"WEB","url":"https://www.gnutls.org/security-new.html#GNUTLS-SA-2025-11-18"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:13812"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:3477"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:4188"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:4655"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:4943"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:5585"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:5606"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:7329"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:7477"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2025-9820"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/9xxx/CVE-2025-9820.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-9820"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2392528"},{"type":"REPORT","url":"https://gitlab.com/gnutls/gnutls/-/issues/1732"},{"type":"FIX","url":"https://gitlab.com/gnutls/gnutls/-/commit/1d56f96f6ab5034d677136b9d50b5a75dff0faf5"},{"type":"PACKAGE","url":"https://gitlab.com/gnutls/gnutls"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://gitlab.com/gnutls/gnutls","events":[{"introduced":"513570a57da9d354379eef1163385d87aedd4109"},{"fixed":"1d56f96f6ab5034d677136b9d50b5a75dff0faf5"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"3.8.1"},{"last_affected":"3.8.1"},{"introduced":"3.8.2"},{"last_affected":"3.8.2"},{"introduced":"3.8.3"},{"last_affected":"3.8.3"},{"introduced":"3.8.4"},{"last_affected":"3.8.4"},{"introduced":"3.8.5"},{"last_affected":"3.8.5"},{"introduced":"3.8.6"},{"last_affected":"3.8.6"},{"introduced":"3.8.7"},{"last_affected":"3.8.7"},{"introduced":"3.8.8"},{"last_affected":"3.8.8"},{"introduced":"3.8.9"},{"last_affected":"3.8.9"},{"introduced":"3.8.10"},{"last_affected":"3.8.10"}]}}],"versions":["3.8.1","3.8.10","3.8.2","3.8.3","3.8.4","3.8.5","3.8.6","3.8.7","3.8.8","3.8.9"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-9820.json","vanir_signatures_modified":"2026-09-03T08:05:35Z","vanir_signatures":[{"deprecated":false,"digest":{"line_hashes":["203081701998267077212086687325320656047","181103679989110600517533548016277704131","39853057649325964027587234063574987404","259048303717493519631185376627170807634","235519305165135146109306515938527170000","15365237184004671114243159335111336950","128494245172431755117396483110562105716","44347100990748648967188547802763753138","328331381237090027273525864829690989806","255687099527695671086163998843993578170","226269730992432168968068826384392231200"],"threshold":0.9},"id":"CVE-2025-9820-2f514dfb","signature_type":"Line","signature_version":"v1","source":"https://gitlab.com/gnutls/gnutls@1d56f96f6ab5034d677136b9d50b5a75dff0faf5","target":{"file":"lib/pkcs11_write.c"}},{"deprecated":false,"digest":{"function_hash":"129252198033229729266867875486069486085","length":734},"id":"CVE-2025-9820-ef29652e","signature_type":"Function","signature_version":"v1","source":"https://gitlab.com/gnutls/gnutls@1d56f96f6ab5034d677136b9d50b5a75dff0faf5","target":{"file":"lib/pkcs11_write.c","function":"gnutls_pkcs11_token_init"}}]}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}