CVE-2025-9820

Publication date 26 January 2026

Last updated 6 July 2026

Ubuntu priority

Low

Why this priority?

Cvss 3 Severity Score

4.0 · Medium

Score breakdown

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.

Read the notes from the security team

Why is this CVE low priority?

GnuTLS developers have rated this to be low severity

Learn more about Ubuntu priority

Status

Package Ubuntu Release Status
gnutls28 26.04 LTS resolute
Not affected
25.10 questing
Fixed 3.8.9-3ubuntu2.1
25.04 plucky Ignored end of life, was needs-triage
24.04 LTS noble
Fixed 3.8.3-1.1ubuntu3.5
22.04 LTS jammy
Fixed 3.7.3-4ubuntu1.8
20.04 LTS focal
Fixed 3.6.13-2ubuntu1.12+esm2
18.04 LTS bionic
Fixed 3.5.18-1ubuntu1.6+esm3
16.04 LTS xenial
Fixed 3.4.10-4ubuntu1.9+esm3

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Notes

mdeslaur

Ubuntu builds are built with stack protector, mitigating this issue

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
gnutls28

Severity score breakdown

CVSS version: CVSS v3.0

Base score 4.0 · Medium

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

References

Related Ubuntu Security Notices (USN)

Other references

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