CVE-2024-21509 is a medium-severity (CVSS 6.5) CWE-1321 vulnerability in mysql2. A fix is available for mysql2 — see the affected versions and patch details below.
mysql2 vulnerable to Prototype Poisoning
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-21509.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
mysql2npmDescription
Versions of the package mysql2 before 3.9.4 are vulnerable to Prototype Poisoning due to insecure results object creation and improper user input sanitization passed through parserFn in text_parser.js and binary_parser.js.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mysql2 | all versions | 3.9.4npm install mysql2@3.9.4 |
Affected Products
mysql2sidoraresDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mysql2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mysql2 to 3.9.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-21509 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2024-21509 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2024-21509 in your dependencies?
Find it across npm, including transitive dependencies.