{ "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-2026-100633", "tracking": { "current_release_date": "2026-10-20T02:28:59.771049Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-100633", "initial_release_date": "2026-09-26T14:26:49.620373Z", "revision_history": [ { "date": "2026-09-26T14:26:49.620373Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)." }, { "date": "2026-09-26T14:26:55.167357Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-09-27T06:35:03.426713Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (21).| References created (4).| CWES updated (1)." }, { "date": "2026-09-27T06:35:14.223798Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-09-27T15:15:03.912183Z", "number": "5", "summary": "EPSS created.| Unknown change." }, { "date": "2026-09-27T15:15:07.383993Z", "number": "6", "summary": "NCSC Score updated." }, { "date": "2026-09-28T12:43:41.337654Z", "number": "7", "summary": "CVSS created.| CWES created (1).| Products created (3).| References created (2).| Description created for source.| Unknown change.| Product Identifiers created (1)." }, { "date": "2026-09-28T12:43:42.979484Z", "number": "8", "summary": "NCSC Score updated." }, { "date": "2026-09-29T16:13:13.938464Z", "number": "9", "summary": "EPSS created.| Unknown change." }, { "date": "2026-09-29T16:13:21.161988Z", "number": "10", "summary": "NCSC Score updated." }, { "date": "2026-10-06T14:28:10.226964Z", "number": "11", "summary": "Unknown change." }, { "date": "2026-10-06T14:28:38.736935Z", "number": "12", "summary": "NCSC Score updated." }, { "date": "2026-10-20T02:28:51.019583Z", "number": "13", "summary": "NCSC Score updated." } ], "status": "interim", "version": "13" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/>=3.8.0|<=3.8.4", "product": { "name": "vers:unknown/>=3.8.0|<=3.8.4", "product_id": "CSAFPID-9479032", "product_identification_helper": { "cpe": "cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*" } } } ], "category": "product_name", "name": "siyuan" } ], "category": "vendor", "name": "B3log" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:semver/3.8.0|<3.8.4", "product": { "name": "vers:semver/3.8.0|<3.8.4", "product_id": "CSAFPID-9479033" } }, { "category": "product_version_range", "name": "vers:semver/3.8.4", "product": { "name": "vers:semver/3.8.4", "product_id": "CSAFPID-9479034" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.0", "product": { "name": "vers:unknown/v3.8.0", "product_id": "CSAFPID-9085030" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.1", "product": { "name": "vers:unknown/v3.8.1", "product_id": "CSAFPID-9150602" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.1-beta.1", "product": { "name": "vers:unknown/v3.8.1-beta.1", "product_id": "CSAFPID-9085029" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.1-beta.4", "product": { "name": "vers:unknown/v3.8.1-beta.4", "product_id": "CSAFPID-9085028" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.1-beta.5", "product": { "name": "vers:unknown/v3.8.1-beta.5", "product_id": "CSAFPID-9085027" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.1-beta.6", "product": { "name": "vers:unknown/v3.8.1-beta.6", "product_id": "CSAFPID-9085026" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.2-alpha.1", "product": { "name": "vers:unknown/v3.8.2-alpha.1", "product_id": "CSAFPID-9150601" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.2-alpha.3", "product": { "name": "vers:unknown/v3.8.2-alpha.3", "product_id": "CSAFPID-9150600" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.2-alpha.4", "product": { "name": "vers:unknown/v3.8.2-alpha.4", "product_id": "CSAFPID-9150599" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.2-alpha.5", "product": { "name": "vers:unknown/v3.8.2-alpha.5", "product_id": "CSAFPID-9150598" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.2-alpha.6", "product": { "name": "vers:unknown/v3.8.2-alpha.6", "product_id": "CSAFPID-9150597" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.3", "product": { "name": "vers:unknown/v3.8.3", "product_id": "CSAFPID-9357316" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.3-alpha.1", "product": { "name": "vers:unknown/v3.8.3-alpha.1", "product_id": "CSAFPID-9357322" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.3-alpha.2", "product": { "name": "vers:unknown/v3.8.3-alpha.2", "product_id": "CSAFPID-9357321" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.3-alpha.3", "product": { "name": "vers:unknown/v3.8.3-alpha.3", "product_id": "CSAFPID-9357320" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.3-beta.1", "product": { "name": "vers:unknown/v3.8.3-beta.1", "product_id": "CSAFPID-9357319" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.4-beta.1", "product": { "name": "vers:unknown/v3.8.4-beta.1", "product_id": "CSAFPID-9357318" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.4-beta.2", "product": { "name": "vers:unknown/v3.8.4-beta.2", "product_id": "CSAFPID-9357317" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.4-beta.3", "product": { "name": "vers:unknown/v3.8.4-beta.3", "product_id": "CSAFPID-9357315" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.4-beta.4", "product": { "name": "vers:unknown/v3.8.4-beta.4", "product_id": "CSAFPID-9357314" } }, { "category": "product_version_range", "name": "vers:unknown/v3.8.4-beta.5", "product": { "name": "vers:unknown/v3.8.4-beta.5", "product_id": "CSAFPID-9357313" } } ], "category": "product_name", "name": "siyuan" } ], "category": "vendor", "name": "siyuan-note" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-100633", "cwe": { "id": "CWE-863", "name": "Incorrect Authorization" }, "notes": [ { "category": "description", "text": "SiYuan is a self-hosted personal knowledge management system. In versions 3.8.0 through 3.8.3, the MCP file tool's sensitive-path guard (util.IsForbiddenAbsPath(), invoked from resolvePath()) is applied only to the allowed root of recursive operations and not to each resolved descendant path — an incomplete fix for GHSA-c8r8-95hg-mp34. An authenticated administrator using the in-app Agent or the external MCP server can therefore bypass the protected-workspace-file denylist: file.grep can return matching lines from non-hidden protected descendants (for example conf/conf.json, TLS keys, data/snippets/conf.json, data/templates/, data/.siyuan/publishAccess.json, notebook .siyuan internals, or the kernel log), file.copy can copy protected descendants to an ordinary path where file.read can then retrieve them, and unzip can overwrite protected descendants using ordinary, lexically contained ZIP member names. Because file.grep is globally classified as a safe action, it receives no per-call confirmation, and the confirmation cards for file.copy and unzip show only the allowed root arguments. This issue is fixed in version 3.8.4. Suggested title: SiYuan 3.8.0 through 3.8.3 Sensitive-Path Guard Bypass in Recursive MCP File Operations.", "title": "cveprojectv5 - https://www.cve.org/CVERecord?id=CVE-2026-100633" }, { "category": "description", "text": "SiYuan is a self-hosted personal knowledge management system. In versions 3.8.0 through 3.8.3, the MCP file tool's sensitive-path guard (util.IsForbiddenAbsPath(), invoked from resolvePath()) is applied only to the allowed root of recursive operations and not to each resolved descendant path — an incomplete fix for GHSA-c8r8-95hg-mp34. An authenticated administrator using the in-app Agent or the external MCP server can therefore bypass the protected-workspace-file denylist: file.grep can return matching lines from non-hidden protected descendants (for example conf/conf.json, TLS keys, data/snippets/conf.json, data/templates/, data/.siyuan/publishAccess.json, notebook .siyuan internals, or the kernel log), file.copy can copy protected descendants to an ordinary path where file.read can then retrieve them, and unzip can overwrite protected descendants using ordinary, lexically contained ZIP member names. Because file.grep is globally classified as a safe action, it receives no per-call confirmation, and the confirmation cards for file.copy and unzip show only the allowed root arguments. This issue is fixed in version 3.8.4. Suggested title: SiYuan 3.8.0 through 3.8.3 Sensitive-Path Guard Bypass in Recursive MCP File Operations.", "title": "osvgit - https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/GIT%2FCVE-2026-100633.json?alt=media" }, { "category": "description", "text": "SiYuan is a self-hosted personal knowledge management system. In versions 3.8.0 through 3.8.3, the MCP file tool's sensitive-path guard (util.IsForbiddenAbsPath(), invoked from resolvePath()) is applied only to the allowed root of recursive operations and not to each resolved descendant path — an incomplete fix for GHSA-c8r8-95hg-mp34. An authenticated administrator using the in-app Agent or the external MCP server can therefore bypass the protected-workspace-file denylist: file.grep can return matching lines from non-hidden protected descendants (for example conf/conf.json, TLS keys, data/snippets/conf.json, data/templates/, data/.siyuan/publishAccess.json, notebook .siyuan internals, or the kernel log), file.copy can copy protected descendants to an ordinary path where file.read can then retrieve them, and unzip can overwrite protected descendants using ordinary, lexically contained ZIP member names. Because file.grep is globally classified as a safe action, it receives no per-call confirmation, and the confirmation cards for file.copy and unzip show only the allowed root arguments. This issue is fixed in version 3.8.4. Suggested title: SiYuan 3.8.0 through 3.8.3 Sensitive-Path Guard Bypass in Recursive MCP File Operations.", "title": "nvd - https://nvd.nist.gov/vuln/detail/CVE-2026-100633" }, { "category": "other", "text": "0.00325", "title": "EPSS" }, { "category": "other", "text": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/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", "title": "CVSSV4" }, { "category": "other", "text": "8.5", "title": "CVSSV4 base score" }, { "category": "other", "text": "4.0", "title": "NCSC Score" }, { "category": "other", "text": "Is related to CWE-863 (Incorrect Authorization)", "title": "NCSC Score top increasing factors" }, { "category": "other", "text": "Is related to (a version of) an uncommon product, Is related to an uncommon product vendor, There is cwe data available from source Nvd", "title": "NCSC Score top decreasing factors" } ], "product_status": { "known_affected": [ "CSAFPID-9479032", "CSAFPID-9479033", "CSAFPID-9085030", "CSAFPID-9150602", "CSAFPID-9085029", "CSAFPID-9085028", "CSAFPID-9085027", "CSAFPID-9085026", "CSAFPID-9150601", "CSAFPID-9150600", "CSAFPID-9150599", "CSAFPID-9150598", "CSAFPID-9150597", "CSAFPID-9357316", "CSAFPID-9357322", "CSAFPID-9357321", "CSAFPID-9357320", "CSAFPID-9357319", "CSAFPID-9357318", "CSAFPID-9357317", "CSAFPID-9357315", "CSAFPID-9357314", "CSAFPID-9357313" ], "known_not_affected": [ "CSAFPID-9479034" ] }, "references": [ { "category": "external", "summary": "Source - ncscclear", "url": "https://vulnerabilities.ncsc.nl/manual/CVE-2026-100633" }, { "category": "external", "summary": "Source - nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-100633" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss" }, { "category": "external", "summary": "Source - cveprojectv5", "url": "https://www.cve.org/CVERecord?id=CVE-2026-100633" }, { "category": "external", "summary": "Source - osv", "url": "https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/GIT%2FCVE-2026-100633.json?alt=media" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd; osv", "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-9g6v-r3xf-673q" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd; osv", "url": "https://www.vulncheck.com/advisories/siyuan-3.8.0-through-3.8.3-path-traversal-via-mcp-file-operations" }, { "category": "external", "summary": "Reference - osv", "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100633.json" }, { "category": "external", "summary": "Reference - osv", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-100633" } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N", "baseScore": 6.5, "baseSeverity": "MEDIUM" }, "products": [ "CSAFPID-9085026", "CSAFPID-9085027", "CSAFPID-9085028", "CSAFPID-9085029", "CSAFPID-9085030", "CSAFPID-9150597", "CSAFPID-9150598", "CSAFPID-9150599", "CSAFPID-9150600", "CSAFPID-9150601", "CSAFPID-9150602", "CSAFPID-9357313", "CSAFPID-9357314", "CSAFPID-9357315", "CSAFPID-9357316", "CSAFPID-9357317", "CSAFPID-9357318", "CSAFPID-9357319", "CSAFPID-9357320", "CSAFPID-9357321", "CSAFPID-9357322", "CSAFPID-9479032", "CSAFPID-9479033" ] } ], "title": "CVE-2026-100633" } ] }