CVE-2025-9820
MEDIUMA 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.
Published: 1/26/2026Modified: 5/12/2026
References (16)
https://access.redhat.com/errata/RHSA-2026:13812https://access.redhat.com/errata/RHSA-2026:3477https://access.redhat.com/errata/RHSA-2026:4188https://access.redhat.com/errata/RHSA-2026:4655https://access.redhat.com/errata/RHSA-2026:4943https://access.redhat.com/errata/RHSA-2026:5585https://access.redhat.com/errata/RHSA-2026:5606https://access.redhat.com/errata/RHSA-2026:7329https://access.redhat.com/errata/RHSA-2026:7477https://access.redhat.com/security/cve/CVE-2025-9820https://bugzilla.redhat.com/show_bug.cgi?id=2392528https://gitlab.com/gnutls/gnutls/-/commit/1d56f96f6ab5034d677136b9d50b5a75dff0faf5https://gitlab.com/gnutls/gnutls/-/issues/1732https://www.gnutls.org/security-new.html#GNUTLS-SA-2025-11-18http://www.openwall.com/lists/oss-security/2025/11/20/2https://cert-portal.siemens.com/productcert/html/ssa-032379.html