CVE-2025-9820
Published: November 25, 2025Last modified: December 4, 2025
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 4 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | LOW |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
Notes
Fixed by: https://gitlab.com/gnutls/gnutls/-/commit/1d56f96f6ab5034d677136b9d50b5a75dff0faf5 (3.8.11)
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | gnutls | Fixed (3.7.11-r1) |
| 25 LTS | gnutls | Fixed (3.8.11-r0) | |
| Stream | gnutls | Fixed (3.8.11-r0) |
References
- http://www.openwall.com/lists/oss-security/2025/11/20/2
- https://access.redhat.com/security/cve/CVE-2025-9820
- https://bugzilla.redhat.com/show_bug.cgi?id=2392528
- 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