{"id":"GHSA-35hp-hqmv-8qg8","revision":"e2d996cc75134fee9a19ce16faa5e041","records":[{"revision":"e2d996cc75134fee9a19ce16faa5e041","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-35hp-hqmv-8qg8","aliases":["CVE-2026-30246","GO-2026-5069"],"title":"Fiber's cache middleware default key generator ignores query string, causing response mix-up across distinct query parameters","description":"### Summary\nFiber cache middleware's default key generator uses only `c.Path()` and does not include the query string.\nAs a result, requests like `/?id=1` and `/?id=2` can map to the same cache key and share the same cached response.\n\nThis can cause response mix-up (cache poisoning-like behavior) for endpoints where response content depends on query parameters.\n\n### Details\nDefault configuration in cache middleware:\n\n- `KeyGenerator: func(c fiber.Ctx) string { return utils.CopyString(c.Path()) }`\n\nReferences:\n- https://github.com/gofiber/fiber/blob/main/middleware/cache/config.go#L90-L92\n- https://github.com/gofiber/fiber/blob/main/middleware/cache/cache_test.go#L599-L621\n\nThe existing test demonstrates that when handler output depends on query parameter `id`, a second request with a different query still returns the first cached response (cache hit), confirming query is not part of the default cache key.\n\n### PoC\nMinimal PoC:\n\n```go\npackage main\n\nimport (\n    \"log\"\n\n    \"github.com/gofiber/fiber/v3\"\n    \"github.com/gofiber/fiber/v3/middleware/cache\"\n)\n\nfunc main() {\n    app := fiber.New()\n    app.Use(cache.New()) // default config\n\n    app.Get(\"/\", func(c fiber.Ctx) error {\n        return c.SendString(c.Query(\"id\", \"1\"))\n    })\n\n    log.Fatal(app.Listen(\":3000\"))\n}\n```\n\nReproduction:\n\n1. `GET /?id=1`\n   - Cache miss\n   - Response body: `1`\n2. `GET /?id=2`\n   - Cache hit\n   - Response body: `1` (expected `2`)\n\nLocal verification command used:\n\n```bash\ngo test ./middleware/cache -run Test_Cache_WithNoCacheRequestDirective -count=1\n```\n\nObserved result: test passes, confirming this is current behavior.\n\n### Impact\n- Responses that should vary by query parameters can be mixed between requests.\n- In real deployments, this may leak or corrupt user/tenant-specific content if query parameters influence context or data selection.\n- This is deployment-dependent but security-relevant, and not safe-by-default for query-variant responses.\n\n### Suggested remediation\n- Change default cache key generation to include path + normalized query string (or canonicalized original URL).\n- Keep ability for custom key generators.\n- Add explicit documentation warning that path-only keying is unsafe for query-dependent responses.","state":0,"publishedAt":"2026-04-28T22:28:14+00:00","modifiedAt":"2026-07-24T19:11:27.1908342+00:00","affected":[{"ecosystem":"Go","name":"github.com/gofiber/fiber/v3","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"3.2.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/gofiber/fiber/security/advisories/GHSA-35hp-hqmv-8qg8","https://nvd.nist.gov/vuln/detail/CVE-2026-30246","https://github.com/gofiber/fiber/commit/050ff1ff18511c1475b8ec627460216aaecddd4e","https://github.com/gofiber/fiber/commit/9a0d12c07ed895b84c72987f9288b04137afe5de","https://github.com/gofiber/fiber","https://github.com/gofiber/fiber/blob/main/middleware/cache/cache_test.go#L599-L621","https://github.com/gofiber/fiber/blob/main/middleware/cache/config.go#L90-L92"],"sourceUrl":"https://github.com/advisories/GHSA-35hp-hqmv-8qg8","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-35hp-hqmv-8qg8","identifiers":["GHSA-35hp-hqmv-8qg8","CVE-2026-30246","GO-2026-5069"]},"retained":false,"historicalAffected":[]}],"coverage":[]}