{"id":"CVE-2026-118658","aliases":["DEBIAN-CVE-2026-118658","EUVD-2026-112465","GHSA-23wf-92cp-8pcj","GO-2026-6878","UBUNTU-CVE-2026-118658"],"status":"published","title":"Echo: Arbitrary Scheme Injection in WWWRedirect/NonWWWRedirect Middlewares via X-Forwarded-Proto","description":"Echo is a Go web framework. Prior to 4.15.2 and 5.1.1, Context.Scheme returns values from X-Forwarded-Proto, X-Forwarded-Protocol, or X-Url-Scheme without validating that they are supported web schemes. WWWRedirect and NonWWWRedirect use that value to construct a Location header, so an attacker controlling a forwarded scheme header can cause a redirect to use an arbitrary URI scheme. Exploitation requires an affected redirect middleware and user interaction with the response; the HTTPS-specific redirect variants hardcode HTTPS and are unaffected. This issue is fixed in 4.15.2 and 5.1.1.","severity":{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00186,"percentile":0.08261,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-601"],"published":"2026-10-28T20:17:11Z","modified":"2026-11-05T23:26:00Z","fixes":[{"ecosystem":"Go","package":"github.com/labstack/echo/v5","fixed_in":["5.1.1"],"sources":["ghsa","osv"]},{"ecosystem":"Go","package":"github.com/labstack/echo/v4","fixed_in":["4.15.2"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Go","package":"github.com/labstack/echo/v5","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.1.1"}]}]},{"source":"ghsa","ecosystem":"Go","package":"github.com/labstack/echo/v4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.2"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"golang-github-labstack-echo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.11.1-1","4.11.1-2","4.12.0-1","4.2.1-3"]},{"source":"osv","ecosystem":"Debian:13","package":"golang-github-labstack-echo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.12.0-1"]},{"source":"osv","ecosystem":"Debian:14","package":"golang-github-labstack-echo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.12.0-1"]},{"source":"osv","ecosystem":"Go","package":"github.com/labstack/echo/v5","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.1.1"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/labstack/echo/v4","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"4.15.2"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/labstack/echo/v4","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"4.15.2"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/labstack/echo/v5","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.1.1"}]}]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"golang-github-labstack-echo.v2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.0-1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"golang-github-labstack-echo.v3","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.5-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"golang-github-labstack-echo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.1-2"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"golang-github-labstack-echo.v2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.0-2"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"golang-github-labstack-echo.v3","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.10-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"golang-github-labstack-echo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.11.1-2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"golang-github-labstack-echo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.12.0-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"golang-github-labstack-echo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.12.0-1"]}],"products":[{"vendor":"labstack","product":"echo"},{"vendor":"wikimedia foundation","product":"echo"}],"references":[{"url":"https://github.com/labstack/echo/security/advisories/GHSA-23wf-92cp-8pcj","tags":["x_refsource_CONFIRM","exploit","advisory","web","report"]},{"url":"https://github.com/labstack/echo/commit/ca4f38a474302aabee93c66bdd0052359882e181","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://github.com/labstack/echo/commit/d1d8ad3f99dd9b80542cd0c357d56a8916c515df","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://github.com/labstack/echo/releases/tag/v4.15.2","tags":["x_refsource_MISC","web","report"]},{"url":"https://github.com/labstack/echo/releases/tag/v5.1.1","tags":["x_refsource_MISC","web","report"]},{"url":"https://github.com/labstack/echo/pull/2953","tags":["web","fix"]},{"url":"https://github.com/advisories/GHSA-23wf-92cp-8pcj"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118658.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118658","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-118658","tags":["advisory"]},{"url":"https://github.com/labstack/echo","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-118658","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-118658","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-118658","title":"Echo: Arbitrary Scheme Injection in WWWRedirect/NonWWWRedirect Middlewares via X-Forwarded-Proto","description":"Echo is a Go web framework. Prior to 4.15.2 and 5.1.1, Context.Scheme returns values from X-Forwarded-Proto, X-Forwarded-Protocol, or X-Url-Scheme without validating that they are supported web schemes. WWWRedirect and NonWWWRedirect use that value to construct a Location header, so an attacker controlling a forwarded scheme header can cause a redirect to use an arbitrary URI scheme. Exploitation requires an affected redirect middleware and user interaction with the response; the HTTPS-specific redirect variants hardcode HTTPS and are unaffected. This issue is fixed in 4.15.2 and 5.1.1.","status":"published","published":"2026-10-28T20:17:11.083Z","modified":"2026-11-02T20:44:22.513Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-601"],"updated_at":"2026-11-03T00:01:31.308004Z"}],"euvd":[{"id":"EUVD-2026-112465","description":"Echo is a Go web framework. Prior to 4.15.2 and 5.1.1, Context.Scheme returns values from X-Forwarded-Proto, X-Forwarded-Protocol, or X-Url-Scheme without validating that they are supported web schemes. WWWRedirect and NonWWWRedirect use that value to construct a Location header, so an attacker controlling a forwarded scheme header can cause a redirect to use an arbitrary URI scheme. Exploitation requires an affected redirect middleware and user interaction with the response; the HTTPS-specific redirect variants hardcode HTTPS and are unaffected. This issue is fixed in 4.15.2 and 5.1.1.","status":"published","published":"2026-10-28T20:17:11Z","modified":"2026-11-02T20:44:22Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-03T05:08:36.865312Z"}],"ghsa":[{"id":"GHSA-23wf-92cp-8pcj","title":"Echo has Arbitrary Scheme Injection in WWWRedirect/NonWWWRedirect Middlewares via X-Forwarded-Proto","description":"## Summary\n\nThe `c.Scheme()` method in Echo (`context.go:162-181`) trusts the `X-Forwarded-Proto`, `X-Forwarded-Protocol`, and `X-Url-Scheme` request headers without validating that the value is `http` or `https`. The `WWWRedirect()` and `NonWWWRedirect()` middlewares use this unsanitized scheme to construct redirect URLs, allowing an attacker to inject arbitrary URI schemes into the `Location` response header.\n\n## Affected Components\n\n- `context.go:162-181` - `Scheme()` method returns attacker-controlled value verbatim\n- `middleware/redirect.go:172-184` - `redirectWWW`/`redirectNonWWW` use unsanitized scheme\n\n## Proof of Concept\n\n```\nGET /path HTTP/1.1\nHost: example.com\nX-Forwarded-Proto: javascript\n\nResponse:\nHTTP/1.1 301 Moved Permanently\nLocation: javascript://www.example.com/path\n```\n\nConfirmed injectable schemes: `javascript`, `data`, `vbscript`, `file`, `ftp`, `ssh`, `telnet`, `gopher`.\n\nOnly `WWWRedirect()` and `NonWWWRedirect()` (and `WithConfig` variants) are affected. `HTTPSRedirect`, `HTTPSWWWRedirect`, `HTTPSNonWWWRedirect` are NOT affected (they hardcode `https://`).\n\n## Impact\n\n- Open redirect to arbitrary scheme URLs when app is not behind a proxy that strips `X-Forwarded-Proto`\n- Cache poisoning when behind a CDN that caches redirect responses keyed by path\n- `file://` scheme injection could trigger file access in some browser configurations\n\n## Suggested Fix\n\nWhitelist scheme in `c.Scheme()` to only return `http` or `https`:\n\n```go\nfunc (c *Context) Scheme() string {\n    if c.IsTLS() {\n        return \"https\"\n    }\n    if scheme := c.request.Header.Get(HeaderXForwardedProto); scheme != \"\" {\n        scheme = strings.ToLower(strings.TrimSpace(scheme))\n        if scheme == \"https\" {\n            return \"https\"\n        }\n    }\n    return \"http\"\n}\n```\n\n## Disclosure\n\nSource code review, manually verified with actual HTTP server. Tested on Echo v5.0.4 (latest master).\n\n## Patches\n\nFixed in `github.com/labstack/echo/v5` v5.1.1 and `github.com/labstack/echo/v4` v4.15.2. `Context.Scheme()` now accepts only `http`, `https`, `ws` or `wss` from the `X-Forwarded-Proto`, `X-Forwarded-Protocol` and `X-Url-Scheme` headers, and falls back to `http` for any other value (#2953).\n\n## Workarounds\n\nUpgrade to a patched version. If you cannot upgrade, have your edge proxy overwrite or remove the `X-Forwarded-Proto`, `X-Forwarded-Protocol` and `X-Url-Scheme` request headers.","status":"published","published":"2026-10-28T21:04:10Z","modified":"2026-10-31T12:39:21Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T14:41:42.013329Z"}],"nvd":[{"id":"CVE-2026-118658","description":"Echo is a Go web framework. Prior to 4.15.2 and 5.1.1, Context.Scheme returns values from X-Forwarded-Proto, X-Forwarded-Protocol, or X-Url-Scheme without validating that they are supported web schemes. WWWRedirect and NonWWWRedirect use that value to construct a Location header, so an attacker controlling a forwarded scheme header can cause a redirect to use an arbitrary URI scheme. Exploitation requires an affected redirect middleware and user interaction with the response; the HTTPS-specific redirect variants hardcode HTTPS and are unaffected. This issue is fixed in 4.15.2 and 5.1.1.","status":"published","published":"2026-10-28T21:16:55.827Z","modified":"2026-11-02T21:17:27.93Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-601"],"updated_at":"2026-11-03T00:02:39.144061Z"}],"osv":[{"id":"CVE-2026-118658","title":"Echo: Arbitrary Scheme Injection in WWWRedirect/NonWWWRedirect Middlewares via X-Forwarded-Proto","description":"Echo is a Go web framework. Prior to 4.15.2 and 5.1.1, Context.Scheme returns values from X-Forwarded-Proto, X-Forwarded-Protocol, or X-Url-Scheme without validating that they are supported web schemes. WWWRedirect and NonWWWRedirect use that value to construct a Location header, so an attacker controlling a forwarded scheme header can cause a redirect to use an arbitrary URI scheme. Exploitation requires an affected redirect middleware and user interaction with the response; the HTTPS-specific redirect variants hardcode HTTPS and are unaffected. This issue is fixed in 4.15.2 and 5.1.1.","status":"published","published":"2026-10-28T20:17:11.083Z","modified":"2026-11-05T23:26:00.516303023Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-601"],"updated_at":"2026-11-06T00:02:13.631839Z"},{"id":"DEBIAN-CVE-2026-118658","description":"Echo is a Go web framework. Prior to 4.15.2 and 5.1.1, Context.Scheme returns values from X-Forwarded-Proto, X-Forwarded-Protocol, or X-Url-Scheme without validating that they are supported web schemes. WWWRedirect and NonWWWRedirect use that value to construct a Location header, so an attacker controlling a forwarded scheme header can cause a redirect to use an arbitrary URI scheme. Exploitation requires an affected redirect middleware and user interaction with the response; the HTTPS-specific redirect variants hardcode HTTPS and are unaffected. This issue is fixed in 4.15.2 and 5.1.1.","status":"published","published":"2026-10-28T21:16:55.827Z","modified":"2026-11-03T09:47:28.169662665Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-03T10:27:58.933618Z"},{"id":"GHSA-23wf-92cp-8pcj","title":"Echo has Arbitrary Scheme Injection in WWWRedirect/NonWWWRedirect Middlewares via X-Forwarded-Proto","description":"## Summary\n\nThe `c.Scheme()` method in Echo (`context.go:162-181`) trusts the `X-Forwarded-Proto`, `X-Forwarded-Protocol`, and `X-Url-Scheme` request headers without validating that the value is `http` or `https`. The `WWWRedirect()` and `NonWWWRedirect()` middlewares use this unsanitized scheme to construct redirect URLs, allowing an attacker to inject arbitrary URI schemes into the `Location` response header.\n\n## Affected Components\n\n- `context.go:162-181` - `Scheme()` method returns attacker-controlled value verbatim\n- `middleware/redirect.go:172-184` - `redirectWWW`/`redirectNonWWW` use unsanitized scheme\n\n## Proof of Concept\n\n```\nGET /path HTTP/1.1\nHost: example.com\nX-Forwarded-Proto: javascript\n\nResponse:\nHTTP/1.1 301 Moved Permanently\nLocation: javascript://www.example.com/path\n```\n\nConfirmed injectable schemes: `javascript`, `data`, `vbscript`, `file`, `ftp`, `ssh`, `telnet`, `gopher`.\n\nOnly `WWWRedirect()` and `NonWWWRedirect()` (and `WithConfig` variants) are affected. `HTTPSRedirect`, `HTTPSWWWRedirect`, `HTTPSNonWWWRedirect` are NOT affected (they hardcode `https://`).\n\n## Impact\n\n- Open redirect to arbitrary scheme URLs when app is not behind a proxy that strips `X-Forwarded-Proto`\n- Cache poisoning when behind a CDN that caches redirect responses keyed by path\n- `file://` scheme injection could trigger file access in some browser configurations\n\n## Suggested Fix\n\nWhitelist scheme in `c.Scheme()` to only return `http` or `https`:\n\n```go\nfunc (c *Context) Scheme() string {\n    if c.IsTLS() {\n        return \"https\"\n    }\n    if scheme := c.request.Header.Get(HeaderXForwardedProto); scheme != \"\" {\n        scheme = strings.ToLower(strings.TrimSpace(scheme))\n        if scheme == \"https\" {\n            return \"https\"\n        }\n    }\n    return \"http\"\n}\n```\n\n## Disclosure\n\nSource code review, manually verified with actual HTTP server. Tested on Echo v5.0.4 (latest master).\n\n## Patches\n\nFixed in `github.com/labstack/echo/v5` v5.1.1 and `github.com/labstack/echo/v4` v4.15.2. `Context.Scheme()` now accepts only `http`, `https`, `ws` or `wss` from the `X-Forwarded-Proto`, `X-Forwarded-Protocol` and `X-Url-Scheme` headers, and falls back to `http` for any other value (#2953).\n\n## Workarounds\n\nUpgrade to a patched version. If you cannot upgrade, have your edge proxy overwrite or remove the `X-Forwarded-Proto`, `X-Forwarded-Protocol` and `X-Url-Scheme` request headers.","status":"published","published":"2026-10-28T21:04:10Z","modified":"2026-11-05T23:26:00.516303023Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-601"],"updated_at":"2026-11-06T00:02:13.631839Z"},{"id":"UBUNTU-CVE-2026-118658","description":"Echo is a Go web framework. Prior to 4.15.2 and 5.1.1, Context.Scheme returns values from X-Forwarded-Proto, X-Forwarded-Protocol, or X-Url-Scheme without validating that they are supported web schemes. WWWRedirect and NonWWWRedirect use that value to construct a Location header, so an attacker controlling a forwarded scheme header can cause a redirect to use an arbitrary URI scheme. Exploitation requires an affected redirect middleware and user interaction with the response; the HTTPS-specific redirect variants hardcode HTTPS and are unaffected. This issue is fixed in 4.15.2 and 5.1.1.","status":"published","published":"2026-10-28T21:16:00Z","modified":"2026-11-05T04:42:51Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-05T13:33:25.727744Z"},{"id":"GO-2026-6878","title":"Arbitrary Scheme Injection in WWWRedirect/NonWWWRedirect Middlewares via X-Forwarded-Proto in github.com/labstack/echo","description":"Arbitrary Scheme Injection in WWWRedirect/NonWWWRedirect Middlewares via X-Forwarded-Proto in github.com/labstack/echo","status":"published","published":"2026-11-05T22:54:32Z","modified":"2026-11-05T23:15:15.416084165Z","updated_at":"2026-11-06T00:02:13.631839Z"}]}}