CVE-2026-119285
Fiber: CORS wildcard origins matched without a dot boundary, allowing credentialed cross-origin reads
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/gofiber/fiber/v2 | >= 2.52.1, <= 2.52.2 | 2.52.3 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Gofiber | Fiber | from 2.52.1, before 2.52.3 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-g5jq-qmqr-qrwf
- https://github.com/gofiber/fiber/security/advisories/GHSA-g5jq-qmqr-qrwf
- https://nvd.nist.gov/vuln/detail/CVE-2026-119285
- https://github.com/gofiber/fiber/pull/2915
- https://github.com/gofiber/fiber/commit/1aac6f618b6bd3e159d2449acb4232a2170b976b
- https://github.com/gofiber/fiber/releases/tag/v2.52.3