{"id":"CVE-2026-119285","published":"2026-10-29T22:17:01.367","lastModified":"2026-10-29T22:17:01.367","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.","cvssScore":5.9,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","cwes":["CWE-346","CWE-942"],"vendors":[],"products":[],"references":[{"url":"https://github.com/gofiber/fiber/commit/1aac6f618b6bd3e159d2449acb4232a2170b976b","tags":[]},{"url":"https://github.com/gofiber/fiber/pull/2915","tags":[]},{"url":"https://github.com/gofiber/fiber/releases/tag/v2.52.3","tags":[]},{"url":"https://github.com/gofiber/fiber/security/advisories/GHSA-g5jq-qmqr-qrwf","tags":[]}],"exploitRefs":[{"url":"https://github.com/gofiber/fiber/commit/1aac6f618b6bd3e159d2449acb4232a2170b976b","tags":[]},{"url":"https://github.com/gofiber/fiber/pull/2915","tags":[]},{"url":"https://github.com/gofiber/fiber/releases/tag/v2.52.3","tags":[]},{"url":"https://github.com/gofiber/fiber/security/advisories/GHSA-g5jq-qmqr-qrwf","tags":[]}],"hasPoc":true,"ai":null}