CVE-2026-62387: Grav < 1.0.0-rc.16 CORS Misconfiguration via API Plugin
The Grav API plugin (getgrav/grav-plugin-api) before 1.0.0-rc.16 shipped Access-Control-Allow-Origin: as its default CORS configuration on all responses, including authenticated endpoints and preflight (OPTIONS) responses. Because the plugin accepts credentials via the Authorization and X-API-Token headers (set programmatically by JavaScript rather than via cookies), an attacker who obtains a valid access token (e.g., via log leakage, Referer headers, browser history, or network capture) can issue fully authenticated cross-origin requests from any malicious website to read sensitive data and perform write operations as the token's user. Fixed in 1.0.0-rc.16.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
getgrav/grav-plugin-apito a version that resolves this vulnerability.Fixed in 1.0.0-rc.16 - Configuration
Ensure Access-Control-Allow-Origin is not set to "*" for authenticated endpoints and preflight (OPTIONS) responses; use the fixed plugin version to eliminate the default wildcard CORS behavior.
Grav API plugin (getgrav/grav-plugin-api) Access-Control-Allow-Origin = *
Event History
Frequently Asked Questions
What is the severity of CVE-2026-62387?
The severity of CVE-2026-62387 is classified as high with a score of 7.1.
How do I fix CVE-2026-62387?
To fix CVE-2026-62387, upgrade the Grav API plugin to version 1.0.0-rc.16 or later.
What does CVE-2026-62387 affect?
CVE-2026-62387 affects the Grav API plugin prior to version 1.0.0-rc.16.
What vulnerabilities does CVE-2026-62387 introduce?
CVE-2026-62387 introduces a CORS misconfiguration that may allow unauthorized access to authenticated endpoints.
What is the default CORS configuration for CVE-2026-62387?
The default CORS configuration for CVE-2026-62387 allows all origins by using Access-Control-Allow-Origin: *.