Fiber is an Express inspired web framework written in Go. From 2.52.1 until 2.52.3, the CORS middleware's validateDomain wildcard matcher in middleware/cors/utils.go strips the scheme and checks only a host suffix without requiring a dot boundary. An application configured with a wildcard-subdomain AllowOrigins value and AllowCredentials enabled can reflect an unrelated attacker-controlled origin whose host merely ends with the configured base domain. A user who visits that origin can expose authenticated cross-origin responses to the attacker's page; empty-label origins and later comma-space parsing hardening are outside this advisory. This issue is fixed in version 2.52.3.
History

Fri, 06 Nov 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Wed, 04 Nov 2026 02:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 29 Oct 2026 22:30:00 +0000

Type Values Removed Values Added
First Time appeared Gofiber
Gofiber fiber
Vendors & Products Gofiber
Gofiber fiber

Thu, 29 Oct 2026 21:45:00 +0000

Type Values Removed Values Added
Description Fiber is an Express inspired web framework written in Go. From 2.52.1 until 2.52.3, the CORS middleware's validateDomain wildcard matcher in middleware/cors/utils.go strips the scheme and checks only a host suffix without requiring a dot boundary. An application configured with a wildcard-subdomain AllowOrigins value and AllowCredentials enabled can reflect an unrelated attacker-controlled origin whose host merely ends with the configured base domain. A user who visits that origin can expose authenticated cross-origin responses to the attacker's page; empty-label origins and later comma-space parsing hardening are outside this advisory. This issue is fixed in version 2.52.3.
Title Fiber: CORS wildcard origins matched without a dot boundary, allowing credentialed cross-origin reads
Weaknesses CWE-346
CWE-942
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-10-29T21:36:02.199Z

Updated: 2026-11-04T01:55:09.920Z

Reserved: 2026-10-29T18:50:28.065Z

Link: CVE-2026-119285

cve-icon Vulnrichment

Updated: 2026-11-04T01:55:04.788Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-29T22:17:01.367

Modified: 2026-11-04T02:17:19.083

Link: CVE-2026-119285

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-29T21:36:02Z

Links: CVE-2026-119285 - Bugzilla