CVE-2025-9820
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.
- Score
- CVSS 3.1 4.0 Medium
- Status
- Deferred - secalert@redhat.com
- Published
- 2026-01-26
- Last modified
- 2026-10-14
- Weaknesses
- CWE-121
Affected products
- Ceph Storage (Redhat)
- Cert Manager (Redhat)
- Discovery (Redhat)
- Enterprise Linux (Redhat)
- Hummingbird (Redhat)
- Insights Proxy (Redhat)
- Openshift (Redhat)
- Rhosemc (Redhat)
- Rhui (Redhat)
- Simatic Cn 4100 (Siemens)
References
- https://access.redhat.com/errata/RHSA-2026:13812
- https://access.redhat.com/errata/RHSA-2026:3477
- https://access.redhat.com/errata/RHSA-2026:4188
- https://access.redhat.com/errata/RHSA-2026:4655
- https://access.redhat.com/errata/RHSA-2026:4943
- https://access.redhat.com/errata/RHSA-2026:5585
- https://access.redhat.com/errata/RHSA-2026:5606
- https://access.redhat.com/errata/RHSA-2026:7329
- https://access.redhat.com/errata/RHSA-2026:7477
- https://access.redhat.com/errata/RHSA-2026:82347
- https://access.redhat.com/errata/RHSA-2026:82354
- https://access.redhat.com/errata/RHSA-2026:82372
- https://access.redhat.com/errata/RHSA-2026:82857
- https://access.redhat.com/security/cve/CVE-2025-9820
- https://bugzilla.redhat.com/show_bug.cgi?id=2392528
- https://gitlab.com/gnutls/gnutls/-/commit/1d56f96f6ab5034d677136b9d50b5a75dff0faf5
- https://gitlab.com/gnutls/gnutls/-/issues/1732
- https://www.gnutls.org/security-new.html#GNUTLS-SA-2025-11-18
- http://www.openwall.com/lists/oss-security/2025/11/20/2
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html
