CVE-2026-54719: goshs File-based .goshs ACL Authorization Bypass Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-rmxw-pq4x-3fvh",
  "modified" : "2026-07-28T21:59:48Z",
  "published" : "2026-07-28T21:59:48Z",
  "aliases" : [ "CVE-2026-54719" ],
  "summary" : "goshs: File-based .goshs ACL authorization bypass via the ?bulk zip-download route (unauthenticated read; residual of GHSA-wvhv-qcqf-f3cx)",
  "details" : "GHSA-wvhv-qcqf-f3cx fixed the per-folder .goshs ACL bypass on the state-changing routes (PUT/POST upload/?mkdir/?delete) and added recursive ACL resolution, and its description states the read/list path correctly enforces .goshs. That premise does not hold for the ?bulk zip-download route. bulkDownload (httpserver/updown.go) takes one or more ?file= parameters, runs each through sanitizePath(fs.Webroot, file), and streams the contents back as a ZIP without ever calling findEffectiveACL/applyCustomAuth. It is dispatched from earlyBreakParameters (?bulk) before the normal doDir/doFile/sendFile flow that performs the ACL check. An unauthenticated attacker can therefore read any file under the webroot protected solely by a .goshs ACL, bypassing both the folder auth (401 on the normal path) and the per-file block list (404 on the normal path). Same authorization-inconsistency root cause as the original advisory, surviving on a read route the fix did not cover.\n\nProof of concept (live, against the fixed v2.1.0 build which includes fix commit f212c4f4, served with no global -b auth, only a per-folder .goshs):\n  GET /protected/secret.txt              -> 401 (ACL enforced on normal path)\n  GET /protected/secret.txt -u admin:admin -> 200\n  GET /?bulk&file=/protected/secret.txt  -> 200, zip contains the protected file contents  (BYPASS)\n  GET /?bulk&file=/protected/blocked.txt -> 200, zip contains the block-listed file        (block bypass)\n  GET /protected/secret.txt?share        -> 403 'Sharing disabled when auth is disabled'    (correctly gated, NOT a bypass)\n\nImpact: any unauthenticated network attacker can read files an operator protected with the documented per-folder .goshs ACL/basic-auth feature, by requesting them through ?bulk. Confidentiality only (the write/delete equivalents were closed by GHSA-wvhv-qcqf-f3cx). Applies to deployments relying on .goshs as the access boundary (a server-wide -b basic auth, if configured, also gates ?bulk via its middleware).\n\nRemediation: enforce the effective .goshs ACL inside bulkDownload for every requested file exactly as sendFile/processDir do (resolve findEffectiveACL(filepath.Dir(absPath)) + applyCustomAuth + honor acl.Block), or route ?bulk through the same authorization gate as the normal read path. Audit ?cbDown and other alternate read routes for the same gap.\n\nCredit: anir0y (independent security research).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/patrickhener/goshs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.1.4"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/patrickhener/goshs/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.1.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.1.0"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "goshs.de/goshs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.1.4"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "goshs.de/goshs/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.1.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.1.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/goshs-labs/goshs/security/advisories/GHSA-rmxw-pq4x-3fvh"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/goshs-labs/goshs/commit/7cf911a26ace737e1a55b7dc073e307a25f7fd1d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/goshs-labs/goshs"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/goshs-labs/goshs/releases/tag/v2.1.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-862", "CWE-863" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-28T21:59:48Z",
    "nvd_published_at" : null
  }
}