CVE-2025-9820Stack-based Buffer Overflow in Gnutls28

Severity
4.0MEDIUMNVD
OSV5.3
EPSS
0.0%
top 99.08%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedJan 26
Latest updateFeb 16

Description

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 privileg

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LExploitability: 2.5 | Impact: 1.4

Affected Packages1 packages

debiandebian/gnutls28< gnutls28 3.7.9-2+deb12u6 (bookworm)

🔴Vulnerability Details

3
OSV
gnutls28 vulnerabilities2026-02-16
GHSA
GHSA-337w-h8w7-m899: A flaw was found in the GnuTLS library, specifically in the gnutls_pkcs11_token_init() function that handles PKCS#11 token initialization2026-01-26
OSV
CVE-2025-9820: A flaw was found in the GnuTLS library, specifically in the gnutls_pkcs11_token_init() function that handles PKCS#11 token initialization2026-01-26

📋Vendor Advisories

3
Ubuntu
GnuTLS vulnerabilities2026-02-16
Red Hat
gnutls: Stack-based Buffer Overflow in gnutls_pkcs11_token_init() Function2025-11-18
Debian
CVE-2025-9820: gnutls28 - A flaw was found in the GnuTLS library, specifically in the gnutls_pkcs11_token_...2025

🕵️Threat Intelligence

3
Wiz
CVE-2025-14831 Impact, Exploitability, and Mitigation Steps | Wiz
Wiz
CVE-2025-9820 Impact, Exploitability, and Mitigation Steps | Wiz
Wiz
CVE-2026-1584 Impact, Exploitability, and Mitigation Steps | Wiz

💬Community

1
Bugzilla
CVE-2025-9820 gnutls: Stack-based Buffer Overflow in gnutls_pkcs11_token_init() Function2025-09-02