CVE-2026-53624
MediumCVSS 4.8Exploitation Probability (EPSS)
Low risk12th percentile - higher than 12% of all known CVEs
Summary
In the Fiber web framework for Go prior to version 3.4.0, the helmet middleware incorrectly checks the protocol using c.Protocol() instead of c.Scheme(), causing the Strict-Transport-Security header to never be set even when HSTSMaxAge is configured. This issue is fixed in version 3.4.0.
Risk Assessment
Missing HSTS header exposes the application to downgrade attacks and traffic interception by unauthorized sites, potentially leading to theft of session data or authentication tokens.
Recommendation
Immediately upgrade the Fiber library to version 3.4.0 or later, which correctly sets the Strict-Transport-Security header.
Other vulnerabilities in Fiber
See all- CVE-2026-45045Medium
In the Fiber web framework for Go, prior to versions 3.3.0 and 2.52.14, the BalancerForward proxy helper in middleware/proxy/proxy.go uses Header.Add() instead of Header.Set() when injecting the X-Real-IP header. This allows an attacker to supply a first X-Real-IP value that gets forwarded to upstream servers for logging, rate limiting, and access control.
- CVE-2026-44332Medium
In the Fiber web framework for Go prior to version 3.3.0, the default Authorizer function in the BasicAuth middleware uses short-circuit evaluation that skips password hash comparison for non-existent usernames. This allows reliable remote username enumeration through response timing differences.
Original NVD description (English source)
Fiber is an Express inspired web framework written in Go. Prior to 3.4.0, the helmet middleware in middleware/helmet/helmet.go never sets the Strict-Transport-Security response header even when HSTSMaxAge is configured because it checks c.Protocol() for https instead of c.Scheme(). This issue is fixed in version 3.4.0.