Medium severity · published Jul 8, 2026
CVE-2026-53624
Fiber: HSTS header never set in helmet middleware due to incorrect protocol check
4.8
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 12% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
fiber · gofiber
< 3.4.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53624
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-53624
Patch
https://github.com/gofiber/fiber/commit/04dd4e7754f61768fddccacc79057e416f13e6bf
Issue Tracking
https://github.com/gofiber/fiber/pull/4389
Release Notes
https://github.com/gofiber/fiber/releases/tag/v3.4.0
Exploit
https://github.com/gofiber/fiber/security/advisories/GHSA-gv83-gqw6-9j2c
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