Fiber: CORS wildcard origins matched without a dot boundary, allowing credentialed cross-origin reads
Historical advisory recorded 29 Oct 2026 22:48:55 UTC. Read the latest advisory.
cve-program · CVE-2026-119285
PublishedFiber 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.
Read the publisher's advisoryAffected versions, risk and source history
cve-program · CVE-2026-119285
PublishedFiber: CORS wildcard origins matched without a dot boundary, allowing credentialed cross-origin reads
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.
- Source published
- 29 Oct 2026 21:36:02 UTC
- Source modified
- 29 Oct 2026 21:36:02 UTC
- Saved here
- 29 Oct 2026 22:48:55 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N