CVE-2025-9820 MEDIUM

CVE-2025-9820: Gnutls: stack-based buffer overflow in gnutls_pkcs11_token_init() function

Vendor Red Hat
Product Red Hat Enterprise Linux 6
Weakness CWE-121
Published January 26, 2026
Last update June 30, 2026

CVSS base score

4.0/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

January 26, 2026 CVE published
June 30, 2026 Record updated