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Ubuntu 20.04 LTS MySQL Critical Denial Of Service Vuln USN-8457

Linuxsecurity •LinuxSecurity Advisories • June 24, 2026

Several security issues were fixed in MySQL. Software Description: - mysql-8.0: MySQL database Details: USN-8457-1 fixed several vulnerabilities in MySQL. This update provides the corresponding fixes for MySQL on Ubuntu 20.04 LTS Original advisory details: It was discovered that MySQL Router incorrectly handled repeated TLS protocol upgrade requests. An unauthenticated remote attacker could possibly use this issue to cause MySQL Router to crash, resulting in a denial of service. (CVE-2026-46862) It was discovered that MySQL Server incorrectly handled connection authentication. An unauthenticated remote attacker could possibly use this issue to cause MySQL to crash, resulting in a denial of service. (CVE-2026-46863)

Several security issues were fixed in MySQL.

Software Description:

- mysql-8.0: MySQL database

USN-8457-1 fixed several vulnerabilities in MySQL. This update

provides the corresponding fixes for MySQL on Ubuntu 20.04 LTS

Original advisory details:

It was discovered that MySQL Router incorrectly handled repeated TLS

protocol upgrade requests. An unauthenticated remote attacker could

possibly use this issue to cause MySQL Router to crash, resulting in a

denial of service. (CVE-2026-46862)

It was discovered that MySQL Server incorrectly handled connection

authentication. An unauthenticated remote attacker could possibly use this

issue to cause MySQL to crash, resulting in a denial of service.

The problem can be corrected by updating your system to the following package versions: Ubuntu 20.04 LTS mysql-router 8.0.46-0ubuntu0.20.04.1+esm3 Available with Ubuntu Pro mysql-server 8.0.46-0ubuntu0.20.04.1+esm3 Available with Ubuntu Pro mysql-server-8.0 8.0.46-0ubuntu0.20.04.1+esm3 Available with Ubuntu Pro mysql-server-core-8.0 8.0.46-0ubuntu0.20.04.1+esm3 Available with Ubuntu Pro In general, a standard system update will make all the necessary changes.

CVE-2026-46862, CVE-2026-46863

Ubuntu Security Notice USN-8457-2

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Critical MySQL Denial of Service Vulnerabilities in Ubuntu 20.04 LTS Two critical denial of service vulnerabilities were discovered in MySQL affecting Ubuntu 20.04 LTS. The vulnerabilities, identified as CVE-2026-46862 and CVE-2026-46863, allow unauthenticated remote attackers to crash MySQL Router and MySQL Server, respectively. The issues stem from improper handling of TLS protocol upgrade requests and connection authentication. Users of MySQL version 8.0 on Ubuntu 20.04 LTS are particularly at risk. The vulnerabilities were published on June 16, 2026, and have been addressed in the latest security update. Administrators are advised to update their systems to mitigate the risks. The update is available through standard system updates for Ubuntu Pro users. The potential impact includes service disruption for applications relying on MySQL. 2 sources 72

Extracted Entities

Ubuntu 20.04 LTS MySQL Critical Denial Of Service Vuln USN-8457

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Extracted Entities

Attack Types (1)

Companies (1)

CVEs (2)

CWE Weaknesses (1)

MITRE ATT&CK (1)

Platforms (2)