CVE-2025-21536: Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.39 and prior, 8.4.2 and prior and 9.0.1 and prior. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS

CSIRTS triage

vendor: Oracle product: MySQL ServerOtheraffected: 8.0.39 and prior, 8.4.2 and prior, 9.0.1 and prior

What: An optimizer vulnerability in MySQL Server similar to CVE-2025-21504, exploitable by a high-privileged attacker with network access.
Who is affected: MySQL Server deployments running versions 8.0.39 or earlier, 8.4.2 or earlier, or 9.0.1 or earlier.
Urgency: Low-to-medium urgency; CVSS 4.9 (medium severity), not exploited in the wild, requires high privilege level.
Action: Upgrade MySQL Server to versions after 8.0.39, 8.4.2, or 9.0.1 as applicable.

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EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2025-215360.97% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 59% of all EPSS-scored CVEs.

CVE	CSIRTS overview	External
CVE-2025-21536	coverage & exploitation status	NVD · CVE.org