CVE-2026-119285

Fiber: CORS wildcard origins matched without a dot boundary, allowing credentialed cross-origin reads

Published Oct 29, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-g5jq-qmqr-qrwf Fiber: CORS wildcard origins matched without a dot boundary, allowing credentialed cross-origin reads
History
Type Values Removed Values Added
Metrics ssvc

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

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

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 4, 2026, 1:55 AM
Reserved
Oct 29, 2026, 6:50 PM
Status
Awaiting Analysis
Published
Oct 29, 2026, 10:17 PM
Modified
Nov 4, 2026, 2:17 AM
Severity
Moderate
Public date
Oct 29, 2026, 9:36 PM