CVE-2026-34276
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedVulnerability in the MySQL Server product of Oracle MySQL (component: Server: Group Replication Plugin). Supported versions that are affected are 8.0.0-8.0.45, 8.4.0-8.4.8 and 9.0.0-9.6.0. Easily exploitable vulnerability allows low 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 3.1 Base Score 6.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceVulnerability in Oracle MySQL Group Replication Plugin allows a low-privileged attacker with network access to cause a denial of service (DoS) by hanging or crashing the MySQL Server. The attack exploits a flaw in the Group Replication component which handles distributed transaction coordination across MySQL instances.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 8.0.0, <= 8.0.45>= 8.4.0, <= 8.4.8>= 9.0.0, <= 9.6.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify MySQL versionRun `mysql --version` from command line or execute `SELECT VERSION();` in MySQL clientAffected if version is between 8.0.0 and 8.0.45, between 8.4.0 and 8.4.8, or between 9.0.0 and 9.6.0
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Confirm Group Replication plugin is loadedExecute `SHOW PLUGINS;` and look for 'group_replication' in the Name column, or run `SELECT * FROM information_schema.PLUGINS WHERE PLUGIN_NAME='group_replication';`Affected if group_replication plugin status is 'ACTIVE'
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Check if Group Replication is configuredRun `SHOW VARIABLES LIKE 'group_replication%';` to see if Group Replication has been configured on this MySQL instanceAffected if group_replication_group_name or group_replication_group_seeds variables are set to non-empty values
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Verify network exposureCheck MySQL bind-address in my.cnf/my.ini and review firewall rules or network ACLs controlling access to port 3306Affected if MySQL is bound to 0.0.0.0 or an externally accessible IP address and network access is not restricted to trusted users only
You are affected if your MySQL version is in the listed vulnerable ranges AND the Group Replication plugin is active AND your server is network-accessible to low-privileged untrusted users.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedApply Oracle's critical patch update for this vulnerability to upgrade MySQL to a patched version. If immediate patching is not possible, restrict network access to MySQL servers and limit privileges for untrusted users.
MySQL 8.0.46+ (8.0 branch), 8.4.9+ (8.4 branch), or 9.0.1+ (9.0 branch)
- 1. Identify the MySQL Server version currently installed: SELECT VERSION();
- 2. Determine which branch (8.0.x, 8.4.x, or 9.x) your instance is running
- 3. For MySQL 8.0.x: Upgrade to MySQL 8.0.46 or later (latest 8.0.x release)
- 4. For MySQL 8.4.x: Upgrade to MySQL 8.4.9 or later (latest 8.4.x LTS release)
- 5. For MySQL 9.x: Upgrade to MySQL 9.0.1 or later (latest 9.x release)
- 6. Before upgrading in production, test the upgrade in a staging environment
- 7. Back up all databases before performing the upgrade
- 8. Review MySQL upgrade documentation for your specific version transition
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation6.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-34276 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-34276 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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