CVE-2025-9820Gnutls: stack-based buffer overflow in gnutls_pkcs11_token_init() function
Updated under an hour ago ()
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It affects Red Hat Enterprise Linux 10 and 9 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 4.0 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Weakness (CWE)
- CWE-121
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- redhat
- NVD analysis
- Deferred
- Record last updated
- Oct 14, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux | from 0:3.8.10-3.el10_1 not affected | CNA record |
Red Hat RHEL-8 based Middleware Containers redhat:rhosemc | from 7.13.5-4.1777325677 not affected | CNA record |
Red Hat Cert Manager support for Red Hat OpenShift release 1.18 redhat:cert_manager | from 1791459707 not affected | CNA record |
Red Hat Red Hat Ceph Storage 8 redhat:ceph_storage | from 1774002867 not affected | CNA record |
Red Hat Red Hat Discovery 2 redhat:discovery | from 1775668717 not affected | CNA record |
Red Hat Red Hat Hardened Images redhat:hummingbird | from 3.8.12-1.1.hum1 not affected | CNA record |
Red Hat Red Hat Insights proxy 1.5 redhat:insights_proxy | from 1773685509 not affected | CNA record |
Red Hat Red Hat Update Infrastructure 5 redhat:rhui | from 1773670073 not affected | CNA record |
Red Hat Red Hat OpenShift Container Platform 4 redhat:openshift | 4 | CNA record |
Siemens SIMATIC CN 4100 siemens:simatic_cn_4100 (from the name) | before V5.0 | CISA ADP |
References
- https://access.redhat.com/errata/RHSA-2026:13812vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:3477vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:4188vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:4655vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:4943vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:5585vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:5606vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:7329vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:7477vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82347vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82354vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82372vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:82857vendor-advisory, x-refsource-redhat
- https://access.redhat.com/security/cve/CVE-2025-9820vdb-entry, x-refsource-redhat
- https://bugzilla.redhat.com/show_bug.cgi?id=2392528issue-tracking, x-refsource-redhat
- 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
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.