Vulnerability 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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/gofiber/fiber/commit/1aac6f618b6bd3e159d2449acb4232a2170b976b
- https://github.com/gofiber/fiber/pull/2915
- https://github.com/gofiber/fiber/releases/tag/v2.52.3
- https://github.com/gofiber/fiber/security/advisories/GHSA-g5jq-qmqr-qrwf
FAQ
What is CVE-2026-119285?
CVE-2026-119285 is a vulnerability with a CVSS score of 5.9 (MEDIUM). 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 ...
How severe is CVE-2026-119285?
CVE-2026-119285 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-119285?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.