CVE-2025-50092 DoS in MySQL InnoDB: High Privilege Required

Oracle’s July 15, 2025 advisory that introduced CVE‑2025‑50092 describes a denial‑of‑service (DoS) weakness in the MySQL Server product (component: InnoDB) that can be triggered by a high‑privilege actor with network access and results in the server hanging or repeatedly crashing — a sustained or persistent total loss of availability for affected MySQL instances until patched or recovered.

Background / Overview​

MySQL remains one of the most widely deployed relational database engines in enterprise and cloud environments. The CVE entry published on July 15, 2025 identifies the vulnerable component as InnoDB, and Oracle’s advisory maps the affected product ranges precisely: MySQL Server 8.0.0 through 8.0.42, 8.4.0 through 8.4.5, and 9.0.0 through 9.3.0. Oracle classifies the defect as easily exploitable by an attacker with high privileges who has network access via one of MySQL’s supported protocols, with the practical consequence that a successful exploit can cause MySQL to hang or crash repeatedly (complete DoS).
Independent vulnerability trackers and commercial databases reflect the same technical summary and scoring: multiple sources report the CVSS v3.1 vector as AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H with a base score of 4.9 (Medium), and list the same affected version ranges. Those aggregators also note the primary impact is availability (DoS), not confidentiality or integrity.
Why this matters operationally: if a privileged account (for example, a DBA, application service account with elevated rights, or an already‑compromised administrative credential) is misused — intentionally or by an attacker who obtains those credentials — a single crafted action can render the MySQL service unavailable. In production environments that lack high‑availability (HA) or automated failover for the MySQL layer, that can cascade quickly into application downtime, user disruptions, and potential data integrity stress during crash recovery.

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What the advisory actually says (technical summary)​

• Affected component: InnoDB storage engine within MySQL Server.
• Affected versions: 8.0.0 – 8.0.42, 8.4.0 – 8.4.5, 9.0.0 – 9.3.0 (inclusive).
• Attack vector: Network (attacker need network access to a MySQL endpoint).
• Privileges required: High — attacker must already hold elevated MySQL privileges (DBA/SUPER or equivalent).
• Impact: Availability — High (server hang/crash leading to complete DoS).
• CVSS v3.1: 4.9 (Medium), vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.
• Oracle remediation: vendor advisories list patched releases and upgrade guidance in the July 2025 Critical Patch Update (CPU). Recommended vendor upgrades include MySQL packages beyond the affected release endpoints (see remediation section).

These are the load‑bearing technical facts readers and operators must act upon first; they are corroborated in Oracle’s own advisory and multiple independent trackers.

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Attack scenarios and realistic threat model​

Who can exploit this?​

The key gating factor for CVE‑2025‑50092 is privilege. The CVSS vector and vendor notes put Privileges Required at High. That means an unauthenticated remote attacker who has never had an account on the MySQL instance cannot directly exploit this; instead, exploitation scenarios include:

• A legitimate high‑privilege database account is compromised (phished credentials, leaked keys, reused credentials).
• A malicious insider or rogue administrator with legitimate high privileges intentionally triggers the condition.
• An external attacker achieves privilege escalation through another chain (e.g., an application bug that permits executing statements as a privileged MySQL user) and then uses CVE‑2025‑50092 as a follow‑on to take MySQL offline.

Each scenario shares the same profile: the adversary already has some level of trusted access, and this CVE converts that access into powerful availability disruption. Multiple vulnerability databases and vendor advisories describe the same realistic scenario and emphasize the high‑privilege requirement.

Practical impact​

• A successful exploit can produce a sustained denial of service while the attacker continues to issue the crafted input.
• In some environments the crash may be persistent if the service does not automatically recover (for example, due to corrupted state or complex crash recovery requirements).
• For HA deployments (replication groups, clusters), a crash on one node can induce failover activity; if the exploit is repeated against replica nodes or if failover automation is not resilient, applications can suffer extended outages.
• Even when the vulnerability does not provide code‑execution primitives, the operational damage of repeated MySQL crashes is severe: lost availability, transaction rollbacks, and potential manual intervention to rejoin replicas or recover crashed nodes.

Risk aggregation: CVSS 4.9 understates some operational realities. Although numerically “Medium”, the practical business impact in many production environments can be high — particularly where privileged credentials are overly broad, HA is limited, or recovery procedures are manual.

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Evidence, proof and exploitability​

To date, the public advisories do not attach a public proof‑of‑concept (PoC) that achieves remote unauthenticated exploitation — and the vendor’s own description explicitly calls out the high‑privilege requirement. That reduces the short‑term likelihood of broad automated mass exploitation from the internet at large. However:

• Multiple trackers list the vulnerability as easily exploitable for a high‑privileged actor; that phrasing reflects low technical complexity once the privilege barrier is satisfied.
• Attackers targeting application stacks regularly attempt credential harvesting or privilege escalation; once either is achieved, this CVE becomes a trivial and reliable way to cause downtime.
• Enterprise risk is dominated not by initial remote exploitation complexity but by the joinder of this CVE to other, more accessible flaws (credential reuse, exposed management endpoints, lack of two‑factor authentication).

Put plainly: unless your environment enforces least‑privilege, strict credential hygiene, and separation of duties for administrative MySQL accounts, the path from compromise to catastrophic outage is short. Independent advisories and vendor notes are consistent on this point.

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Recommended mitigations — immediate and medium term​

Operators should treat this vulnerability as a remediation priority if they run affected versions. The remedial actions break down into immediate workarounds, patching, and longer‑term hardening.

Immediate actions (first hour)​

• Inventory: Identify every MySQL instance running versions in the affected ranges (8.0.0–8.0.42, 8.4.0–8.4.5, 9.0.0–9.3.0). Scan package metadata, container images, and cloud DB service engine versions.
• Limit network exposure: If any instance is reachable from untrusted networks, apply network controls immediately — firewall rules, security groups, or host‑based ACLs — to restrict MySQL traffic to trusted subnets and management hosts.
• Lock down admin access: Remove or temporarily disable any nonessential high‑privilege MySQL accounts. Enforce multi‑factor authentication (MFA) for systems used to manage database credentials, and rotate privileged credentials that may be suspected of compromise.
• Increase monitoring: Enable stricter auditing for administrative SQL statements, monitor for unusual sessions or repeated failed authentications, and watch for signs of crashes or restart cycles in MySQL logs and host service managers (systemd, container restarts).

Patching (within maintenance window)​

• Apply vendor‑provided updates. Oracle’s July 2025 CPU enumerates fixed versions and instructs operators to upgrade beyond the affected release endpoints. Vendor trackers and commercial advisories list practical upgrade targets (for example, upgrades to MySQL releases that are beyond 8.0.42, 8.4.5, and 9.3.0). Specific upgrade packages referenced by independent trackers include mysql‑upgrade‑8_0_43, mysql‑upgrade‑8_4_6 and mysql‑upgrade‑9_4_0 or later; follow Oracle’s CPU guidance for the exact patch bundle and required post‑update steps.
• When patching: test in staging, confirm replication rejoin behavior, and validate backups and recovery processes before and after the update.

Medium‑term controls (weeks to months)​

• Principle of least privilege: audit and rework roles so few accounts have the ability to execute the statements and operations that can trigger the flaw.
• Credential hygiene: enforce unique credentials, rotate privileged secrets regularly, and require MFA for administrative consoles and vault access.
• Harden management plane: ensure that database management interfaces are only reachable from controlled administrative networks or bastion hosts.
• Automated recovery: build resilient HA/replication with automated safe failover and safe‑state checks so a single node crash does not result in prolonged downtime.
• Incident planning: incorporate DoS / crash scenarios into runbooks and tabletop exercises; ensure DBA and platform teams coordinate on fast failover and recovery.

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Detection and hunting guidance​

If patching cannot be performed immediately, detection is the next best control. Hunting guidance:

• Logs to inspect:
• MySQL error log for repeated crash stack traces, assertions, or InnoDB panic messages.
• Systemd/container service logs showing frequent restarts or OOM events correlated to MySQL.
• Audit logs showing use of high‑privilege statements immediately preceding crashes.
• Indicators:
• Repeated crash/restart cycles on MySQL servers.
• Unexplained hangs where connections stall or queries time out without corresponding resource exhaustion.
• New or anomalous use of administrative accounts from unusual hosts or IP addresses.
• Alerts to create:
• Host monitoring alert on MySQL service restarts above a baseline threshold (e.g., >3 restarts in 15 minutes).
• SIEM correlation rule connecting privileged SQL statements with subsequent crashes within a short window.
• Forensic collection:
• Preserve MySQL error logs, binary logs, and core dumps for post‑mortem.
• Capture the administrative SQL text (if safe and legal) for reproduction in a secure sandbox.

These detection signals and hunting steps are consistent with vendor and CERT guidance for database DoS vulnerabilities.

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Patch-specific considerations and vendor coordination​

Oracle’s CPU and independent trackers list the fixed releases and strongly advise upgrading. In production environments, operators should:

• Read Oracle’s CPU advisory text for the precise upgrade steps and any platform‑specific caveats (post‑upgrade steps such as running mysql_upgrade or checking replication compatibility). Oracle’s advisory is the canonical source.
• Coordinate with cloud and appliance vendors: if you run MySQL as a managed service (for example, vendor‑managed MySQL offerings or vendor‑supplied appliance images), check the vendor’s own security bulletins or support channels for patch availability and scheduled maintenance windows. Do not assume managed services are immediately patched; many vendors offer staged patching. Independent trackers note downstream vendor errata entries (Red Hat, AlmaLinux, Ubuntu, etc.) that map CVE remediation into distribution packages — consult those vendor advisories for their timelines and package names.
• Validate application compatibility: test patched MySQL binaries with representative workloads — focus on replication, InnoDB recovery, and any custom storage‑engine integrations.

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Risk analysis: strengths and weaknesses of the fix, and unresolved risks​

Strengths

• Oracle provided a CVE, a CPU advisory and fixed packages; multiple independent databases confirm the fix and affected ranges — that indicates rapid vendor response and broad coordination.
• The vulnerability’s gating by high privilege reduces immediate exposure to mass‑scanning internet attackers; exploitation requires an initial compromise or insider access, narrowing the attack surface compared with unauthenticated remote RCE flaws.

Weaknesses / residual risks

• The same privilege requirement that reduces mass‑exposure risk also raises the insider/credential‑compromise risk: once credentials are obtained, attackers gain a reliable route to DoS that is trivial to repeat.
• Many real deployments use broad administrative service accounts or share credentials across tooling and CI/CD pipelines; this operational practice increases the chance that an attacker can achieve the required privilege.
• Distribution and vendor patch lag: downstream OS distributions, cloud images, and appliance vendors may take days to weeks to roll fixes into packages and images. Independent trackers document multiple distributor advisories and errata, which shows the fix is widely circulated but also that coordination is necessary. Operators must track vendor errata closely to avoid blind spots.

Unverifiable or uncertain aspects

• Public PoC availability: at the time of publication there is no widely‑trusted, public PoC that demonstrates unauthenticated remote exploitation — consistent with the vendor’s High‑privilege requirement — but attackers could weaponize scriptable patterns once credentials are available. Treat any third‑party PoC code with extreme caution; evaluate only in isolated labs. If an authoritative public exploit appears, treat that as a significant change in threat level.

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Practical checklist (for DBAs and platform engineers)​

• Inventory all MySQL instances and confirm versions against the affected ranges.
• Prioritize patching instances that:
• Are accessible from untrusted networks.
• Use shared or weak administrative credentials.
• Lack replication or robust automatic failover.
• Immediately restrict network access to management ports and block external access to MySQL where possible.
• Rotate and harden privileged accounts; require MFA for vaults and administrative consoles.
• Ensure reliable backups are up‑to‑date and that you have tested point‑in‑time recovery and replica reconstitution procedures.
• Monitor and alert for repeated MySQL crashes, rapid service restarts, and suspicious privileged activity.

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Conclusion​

CVE‑2025‑50092 is a meaningful operational vulnerability: it permits a high‑privilege actor with network access to convert that access into a reliable availability‑impacting denial of service against MySQL Server instances running affected InnoDB code paths. Although the numerical CVSS score sits in the “Medium” band (4.9), the real‑world impact can be severe — particularly in environments that lack strong privilege separation, quick failover, or disciplined credential hygiene. Oracle’s July 15, 2025 advisory and multiple independent trackers confirm the affected versions and the recommended remediation path; operators should inventory, harden, and patch affected systems as a priority.
Act now: identify affected instances, isolate administrative access, and schedule vendor‑recommended upgrades during your next maintenance window. If you cannot patch immediately, apply strict access controls and enhanced monitoring and treat any sign of privileged account compromise as an urgent incident — because once privileges are in hand, this CVE becomes a reliable route to take your MySQL estate offline.

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Source: MSRC Security Update Guide - Microsoft Security Response Center