Improper input validation in MySQL Server - CVE-2026-21936
Published: January 20, 2026
Vulnerability identifier: #VU121737
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-21936
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote privileged user to perform a denial of service (DoS) attack.
The vulnerability exists due to improper input validation within the InnoDB component in MySQL Server. A remote privileged user can exploit this vulnerability to perform a denial of service (DoS) attack.
Affected software
MySQL Server
MySQL Cluster
Anolis OS
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
openEuler
Ubuntu
mecab
mecab-ipadic-EUCJP
mecab-ipadic
mysql-8.0 (Ubuntu package)
mysql-devel
mysql
mysql-common
mysql-config
mysql-test
mysql-server
mysql-libs
mysql-errmsg
mysql-debuginfo
mysql-help
mysql-debugsource
mysql (Red Hat package)
mysql8.4 (Red Hat package)
MySQL Cluster
Anolis OS
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
openEuler
Ubuntu
mecab
mecab-ipadic-EUCJP
mecab-ipadic
mysql-8.0 (Ubuntu package)
mysql-devel
mysql
mysql-common
mysql-config
mysql-test
mysql-server
mysql-libs
mysql-errmsg
mysql-debuginfo
mysql-help
mysql-debugsource
mysql (Red Hat package)
mysql8.4 (Red Hat package)
How to mitigate CVE-2026-21936
Install updates from vendor's website.
MySQL Cluster - addressed in versions 8.0.45, 8.4.8
mecab - update to 0.996-2
mecab-ipadic-EUCJP - update to 2.7.0.20070801-17.0.1
mecab-ipadic - update to 2.7.0.20070801-17.0.1
mysql-8.0 (Ubuntu package) - addressed in versions 8.0.45-0ubuntu0.20.04.1+esm2, 8.0.45-0ubuntu0.22.04.1, 8.0.45-0ubuntu0.24.04.1, 8.4.8-0ubuntu0.25.10.1
mysql-devel - update to 8.0.45-1
mysql - update to 8.0.45-1
mysql-common - update to 8.0.45-1
mysql-config - update to 8.0.45-1
mysql-test - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-server - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-libs - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-errmsg - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-devel - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-common - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-debuginfo - update to 8.0.45-1
mysql-test - update to 8.0.45-1
mysql-server - update to 8.0.45-1
mysql-libs - update to 8.0.45-1
mysql-help - update to 8.0.45-1
mysql-errmsg - update to 8.0.45-1
mysql-debugsource - update to 8.0.45-1
mysql (Red Hat package) - update to 8.0.45-1.el9_7
mysql8.4 (Red Hat package) - update to 8.4.8-1.el10_1
mecab - update to 0.996-2
mecab-ipadic-EUCJP - update to 2.7.0.20070801-17.0.1
mecab-ipadic - update to 2.7.0.20070801-17.0.1
mysql-8.0 (Ubuntu package) - addressed in versions 8.0.45-0ubuntu0.20.04.1+esm2, 8.0.45-0ubuntu0.22.04.1, 8.0.45-0ubuntu0.24.04.1, 8.4.8-0ubuntu0.25.10.1
mysql-devel - update to 8.0.45-1
mysql - update to 8.0.45-1
mysql-common - update to 8.0.45-1
mysql-config - update to 8.0.45-1
mysql-test - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-server - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-libs - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-errmsg - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-devel - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-common - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql - addressed in versions 8.0.45-1, 8.0.45-1.0.1
mysql-debuginfo - update to 8.0.45-1
mysql-test - update to 8.0.45-1
mysql-server - update to 8.0.45-1
mysql-libs - update to 8.0.45-1
mysql-help - update to 8.0.45-1
mysql-errmsg - update to 8.0.45-1
mysql-debugsource - update to 8.0.45-1
mysql (Red Hat package) - update to 8.0.45-1.el9_7
mysql8.4 (Red Hat package) - update to 8.4.8-1.el10_1
External References
Related Security Bulletins
- Improper input validation in MySQL Cluster
- Multiple vulnerabilities in MySQL Server
- openEuler update for mysql
- Ubuntu update for mysql-8.0
- Ubuntu update for mysql-8.0
- Anolis OS update for mysql
- Red Hat Enterprise Linux 10 update for mysql8.4
- Red Hat Enterprise Linux 9 update for mysql
- Red Hat Enterprise Linux 8 update for the mysql:8.0 module
- Red Hat Enterprise Linux 9 update for the mysql:8.4 module
- Red Hat Enterprise Linux 8 update for the mysql:8.4 module
- Anolis OS update for mysql:8.0 module