Quick answers
- Is CVE-2026-101789 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-101789 being exploited in the wild.
- How severe is CVE-2026-101789?
- Medium severity, with a CVSS score of 6.5, published 20 October 2026.
- Which products and versions are affected?
- Oracle MySQL Server 8.4.0–8.4.12, 9.7.0–9.7.3, 26.7.0–26.7.1; Oracle Mysql Cluster 8.0.0–8.0.49, 8.4.0–8.4.12, 9.7.0–9.7.3, 26.7.0–26.7.1.
- Is there a fix for CVE-2026-101789?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-101789 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-101789?
- Check whether you run Oracle MySQL Server or Oracle Mysql Cluster at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A denial-of-service vulnerability exists in the MySQL Server Optimizer component (CVE-2026-101789) that allows a low-privileged authenticated attacker with network access to trigger a hang or crash of the database process. The vulnerability is exploited via multiple protocols and requires only standard login credentials; successful exploitation results in a repeatedly crashable condition affecting availability.
Affected products
- Oracle MySQL Server 8.4.0–8.4.12, 9.7.0–9.7.3, 26.7.0–26.7.1
- Oracle MySQL Cluster 8.0.0–8.0.49, 8.4.0–8.4.12, 9.7.0–9.7.3, 26.7.0–26.7.1
Timeline
- 2026-10-20: disclosed