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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 privilege escalation attacks.

PUBLISHED Reserved 2025-09-02 | Published 2026-01-26 | Updated 2026-02-11 | Assigner redhat




MEDIUM: 4.0CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Problem types

Stack-based Buffer Overflow

Product status

Default status
affected

Default status
affected

Default status
affected

Default status
affected

Default status
affected

Default status
affected

Timeline

2025-09-02:Reported to Red Hat.
2025-11-18:Made public.

References

www.openwall.com/lists/oss-security/2025/11/20/2

access.redhat.com/security/cve/CVE-2025-9820 vdb-entry

bugzilla.redhat.com/show_bug.cgi?id=2392528 (RHBZ#2392528) issue-tracking

gitlab.com/...ommit/1d56f96f6ab5034d677136b9d50b5a75dff0faf5

gitlab.com/gnutls/gnutls/-/issues/1732

www.gnutls.org/security-new.html

cve.org (CVE-2025-9820)

nvd.nist.gov (CVE-2025-9820)

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