Mysql 5.5: CVE-2026-101766 affects MySQL Server, MySQL Cluster (Server: Replication)
Affects mysql-5.5Source GCVE Database
Not known to be exploited · CVSS 4.4 Medium.
Data as of 27 Oct 2026, 08:31 UTC
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10mariadbpkg:deb/ubuntu/mariadb?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10mysql-9.7pkg:deb/ubuntu/mysql-9.7?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSmariadbpkg:deb/ubuntu/mariadb?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSmysql-8.4pkg:deb/ubuntu/mysql-8.4?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSmariadbpkg:deb/ubuntu/mariadb?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSmysql-8.0pkg:deb/ubuntu/mysql-8.0?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Oracle has released security patches for this vulnerability as part of the October 2026 Critical Patch Update. Users should apply the official Oracle patches without delay to remediate the issue. Oracle advises remaining on actively supported versions and promptly applying security updates. Since this is not a cloud service, patching must be performed by the system administrators. No alternative mitigations or workarounds are specified.
Description
CVE-2026-101766 is a security vulnerability affecting MySQL Server and MySQL Cluster, specifically impacting the replication component. It affects multiple MySQL versions including 8.0, 8.4, and 9.7, as well as certain Ubuntu-packaged versions of MySQL 5.5. The vulnerability was publicly disclosed in October 2026 and is classified with medium severity. Oracle has included this vulnerability in its October 2026 Critical Patch Update, which contains numerous security patches across various Oracle products. There are no known exploits in the wild reported at this time.