CVE-2026-63220

CodeIgniter: Spoofable forwarded HTTPS headers in IncomingRequest::isSecure()

Workarounds

Users who cannot upgrade immediately should enforce HTTP-to-HTTPS redirects outside CodeIgniter, for example with Apache .htaccess/virtual host rules, nginx server blocks, Caddy site config, or load balancer redirect rules.

Users should also ensure that reverse proxies strip or overwrite client-supplied X-Forwarded-Proto and Front-End-Https headers before forwarding requests to the application.

IncomingRequest::isSecure() trusted the X-Forwarded-Proto and Front-End-Https headers from any incoming request. In affected deployments, an attacker could spoof these headers and cause the application to incorrectly treat an HTTP request as secure.

This may impact applications that rely on isSecure(), force_https(), forceGlobalSecureRequests, or similar logic to enforce HTTPS-only access or make security-sensitive decisions.

Exploitability depends on deployment configuration. Applications are most exposed if the backend is reachable directly over HTTP, or if a reverse proxy/load balancer forwards client-supplied forwarding headers without stripping or overwriting them.

CVE-2026-63220 has a CVSS score of 4.8 (Medium). The vector is network-reachable, no privileges required, and no user interaction. 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 (4.7.4); upgrading removes the vulnerable code path.

Kodem intelligence

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1. What is CVE-2026-63220? CVE-2026-63220 is a medium-severity security vulnerability in codeigniter4/framework (composer), affecting versions < 4.7.4. It is fixed in 4.7.4.
2. How severe is CVE-2026-63220? CVE-2026-63220 has a CVSS score of 4.8 (Medium). 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.
3. Which versions of codeigniter4/framework are affected by CVE-2026-63220? codeigniter4/framework (composer) versions < 4.7.4 is affected.
4. Is there a fix for CVE-2026-63220? Yes. CVE-2026-63220 is fixed in 4.7.4. Upgrade to this version or later.
5. Is CVE-2026-63220 exploitable, and should I be worried? Whether CVE-2026-63220 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
6. What actually determines whether CVE-2026-63220 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.
7. How do I fix CVE-2026-63220? Upgrade codeigniter4/framework to 4.7.4 or later.

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