CVE-2025-9820CWE-121

CVE-2025-9820

Medium · published January 27, 2026

CVSS v3.1
4.0
EPSS
0%
Percentile
12.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
4.0 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS v4.0
Not supplied
EPSS
0.00222 · 12.1th percentile
Weakness
CWE-121 · Stack-based Buffer Overflow
Published
2026-01-27T01:16Z
References (20)
https://access.redhat.com/errata/RHSA-2026:13812 · [email protected]https://access.redhat.com/errata/RHSA-2026:3477 · [email protected]https://access.redhat.com/errata/RHSA-2026:4188 · [email protected]https://access.redhat.com/errata/RHSA-2026:4655 · [email protected]https://access.redhat.com/errata/RHSA-2026:4943 · [email protected]https://access.redhat.com/errata/RHSA-2026:5585 · [email protected]https://access.redhat.com/errata/RHSA-2026:5606 · [email protected]https://access.redhat.com/errata/RHSA-2026:7329 · [email protected]https://access.redhat.com/errata/RHSA-2026:7477 · [email protected]https://access.redhat.com/errata/RHSA-2026:82347 · [email protected]https://access.redhat.com/errata/RHSA-2026:82354 · [email protected]https://access.redhat.com/errata/RHSA-2026:82372 · [email protected]https://access.redhat.com/errata/RHSA-2026:82857 · [email protected]https://access.redhat.com/security/cve/CVE-2025-9820 · [email protected]https://bugzilla.redhat.com/show_bug.cgi?id=2392528 · [email protected]https://gitlab.com/gnutls/gnutls/-/commit/1d56f96f6ab5034d677136b9d50b5a75dff0faf5 · [email protected]https://gitlab.com/gnutls/gnutls/-/issues/1732 · [email protected]https://www.gnutls.org/security-new.html#GNUTLS-SA-2025-11-18 · [email protected]http://www.openwall.com/lists/oss-security/2025/11/20/2 · af854a3a-2127-422b-91ae-364da2661108https://cert-portal.siemens.com/productcert/html/ssa-032379.html · 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
EPSS history
Timeline
  • 26 JAN 19:58Z
    Gnutls: stack-based buffer overflow in gnutls_pkcs11_token_init() function
    cvelistv5