Summary
python-engineio vulnerable to Cross-Site Request Forgery (CSRF)
WebSocket cross-origin vulnerability
Workarounds
Do not use cookies for client authentication, or else add a CSRF token to the connection URL.
References
https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)
https://www.christian-schneider.net/CrossSiteWebSocketHijacking.html
For more information
If you have any questions or comments about this advisory:
- Open an issue in python-engineio
Impact
This is a Cross-Site Request Forgery (CSRF) vulnerability. It affects Socket.IO and Engine.IO web servers that authenticate clients using cookies.
A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones. Typical impact: state-changing actions performed as the victim without their consent.
CVE-2019-13611 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.9.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
python-engineio version 3.9.0 patches this vulnerability by adding server-side Origin header checks.
Frequently Asked Questions
- What is CVE-2019-13611? CVE-2019-13611 is a high-severity cross-site request forgery (CSRF) vulnerability in python-engineio (pip), affecting versions <= 3.8.2. It is fixed in 3.9.0. A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones.
- How severe is CVE-2019-13611? CVE-2019-13611 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of python-engineio are affected by CVE-2019-13611? python-engineio (pip) versions <= 3.8.2 is affected.
- Is there a fix for CVE-2019-13611? Yes. CVE-2019-13611 is fixed in 3.9.0. Upgrade to this version or later.
- Is CVE-2019-13611 exploitable, and should I be worried? Whether CVE-2019-13611 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2019-13611 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2019-13611? Upgrade
python-engineioto 3.9.0 or later.