{ "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-2026-32940", "tracking": { "current_release_date": "2026-03-27T00:15:40.216844Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-32940", "initial_release_date": "2026-03-18T23:09:18.662527Z", "revision_history": [ { "date": "2026-03-18T23:09:18.662527Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)." }, { "date": "2026-03-18T23:09:29.645677Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-03-19T15:30:57.132844Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)." }, { "date": "2026-03-20T18:25:04.970851Z", "number": "4", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| References created (4).| CWES updated (1)." }, { "date": "2026-03-20T18:25:07.800019Z", "number": "5", "summary": "NCSC Score updated." }, { "date": "2026-03-20T18:29:49.284328Z", "number": "6", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (4).| CWES updated (1)." }, { "date": "2026-03-20T18:29:51.685945Z", "number": "7", "summary": "NCSC Score updated." }, { "date": "2026-03-20T20:39:22.710037Z", "number": "8", "summary": "Unknown change." }, { "date": "2026-03-20T21:41:51.628448Z", "number": "9", "summary": "References created (4)." }, { "date": "2026-03-20T21:59:21.007336Z", "number": "10", "summary": "Source connected.| CVE status created. (valid)| EPSS created." }, { "date": "2026-03-20T21:59:25.580266Z", "number": "11", "summary": "NCSC Score updated." }, { "date": "2026-03-21T13:47:37.215514Z", "number": "12", "summary": "References removed (4)." }, { "date": "2026-03-22T00:52:04.635359Z", "number": "13", "summary": "References created (4)." }, { "date": "2026-03-22T11:25:05.887352Z", "number": "14", "summary": "References removed (4)." }, { "date": "2026-03-23T00:54:15.918914Z", "number": "15", "summary": "References created (4)." }, { "date": "2026-03-23T05:16:12.880603Z", "number": "16", "summary": "References removed (4)." }, { "date": "2026-03-24T10:18:12.001806Z", "number": "17", "summary": "Products connected (1).| Product Identifiers created (1).| Exploits created (2)." }, { "date": "2026-03-24T10:18:22.744400Z", "number": "18", "summary": "NCSC Score updated." }, { "date": "2026-03-24T20:56:38.865785Z", "number": "19", "summary": "References created (4)." }, { "date": "2026-03-24T20:57:20.505175Z", "number": "20", "summary": "NCSC Score updated." }, { "date": "2026-03-27T00:13:52.351149Z", "number": "21", "summary": "Source created.| CVE status created. (valid)| Description created for source.| References created (5)." }, { "date": "2026-03-27T00:13:54.257690Z", "number": "22", "summary": "NCSC Score updated." }, { "date": "2026-03-27T00:13:55.805169Z", "number": "23", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| References created (5).| CWES updated (1)." } ], "status": "interim", "version": "23" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<3.6.1", "product": { "name": "vers:unknown/<3.6.1", "product_id": "CSAFPID-5839032", "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:unknown/<3.6.1", "product": { "name": "vers:unknown/<3.6.1", "product_id": "CSAFPID-5825995" } }, { "category": "product_version_range", "name": "vers:unknown/>=0|<=0.0.0-20260313024916-fd6526133bb3", "product": { "name": "vers:unknown/>=0|<=0.0.0-20260313024916-fd6526133bb3", "product_id": "CSAFPID-5920116" } } ], "category": "product_name", "name": "siyuan" } ], "category": "vendor", "name": "siyuan-note" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-32940", "cwe": { "id": "CWE-184", "name": "Incomplete List of Disallowed Inputs" }, "notes": [ { "category": "description", "text": "# SanitizeSVG bypass via data:text/xml in getDynamicIcon (incomplete fix for CVE-2026-29183)\n\n`SanitizeSVG` blocks `data:text/html` and `data:image/svg+xml` in href attributes but misses `data:text/xml` and `data:application/xml`. Both render SVG with `onload` JavaScript execution (confirmed in Chromium 136, other browsers untested).\n\n`/api/icon/getDynamicIcon` is unauthenticated and serves SVG as `Content-Type: image/svg+xml`. The `content` parameter (type=8) gets embedded into the SVG via `fmt.Sprintf` with no escaping. The sanitizer catches `data:text/html` but `data:text/xml` passes the blocklist -- only three MIME types are checked.\n\nThis is a click-through XSS: victim visits the crafted URL, sees an SVG with an injected link, clicks it. If SiYuan renders these icons via `` tags in the frontend, links aren't interactive there -- the attack needs direct navigation to the endpoint URL or ``/`` embedding.\n\n## Steps to reproduce\n\nAgainst SiYuan v3.6.0 (Docker):\n\n```sh\n# 1. data:text/xml bypass -- element preserved with href intact\ncurl -s --get \"http://127.0.0.1:6806/api/icon/getDynamicIcon\" \\\n --data-urlencode 'type=8' \\\n --data-urlencode 'content=click' \\\n | grep -o ']*>'\n# Output: \n\n# 2. data:text/html is correctly blocked -- href stripped\ncurl -s --get \"http://127.0.0.1:6806/api/icon/getDynamicIcon\" \\\n --data-urlencode 'type=8' \\\n --data-urlencode 'content=alert(1)\">click' \\\n | grep -o ']*>'\n# Output: (href removed)\n\n# 3. data:application/xml also bypasses\ncurl -s --get \"http://127.0.0.1:6806/api/icon/getDynamicIcon\" \\\n --data-urlencode 'type=8' \\\n --data-urlencode 'content=click' \\\n | grep -o ']*>'\n# Output: (href preserved)\n```\n\nJS execution confirmed in Chromium 136 -- `data:text/xml` SVG `onload` fires and posts a message to the parent window via iframe test.\n\n## Vulnerable code\n\n`kernel/util/misc.go` lines 289-293:\n\n```go\nif strings.HasPrefix(val, \"data:\") {\n if strings.Contains(val, \"text/html\") || strings.Contains(val, \"image/svg+xml\") || strings.Contains(val, \"application/xhtml+xml\") {\n continue\n }\n}\n```\n\n`text/xml` and `application/xml` aren't in the list. Both serve SVG with JS execution.\n\n## Impact\n\nReflected XSS on an unauthenticated endpoint. Victim visits the crafted URL, then clicks the injected link in the SVG. No auth needed to craft the URL.\n\nDocker deployments where SiYuan is network-accessible are the clearest target -- the endpoint is reachable directly. In the Electron desktop app, impact depends on `nodeIntegration`/`contextIsolation` settings. Issue #15970 (\"XSS to RCE\") explored that path.\n\nThe deeper issue: the blocklist approach for data: URIs is fragile. `text/xml` and `application/xml` are the gap today, but other MIME types that render active content could surface. An allowlist of safe image types covers the known vectors and future MIME type additions.\n\n## Affected versions\n\nv3.6.0 (latest, confirmed). All versions since `SanitizeSVG` was added to fix CVE-2026-29183.\n\n## Suggested fix\n\nFlip the data: URI check to an allowlist -- only permit safe image types in href:\n\n```go\nif strings.HasPrefix(val, \"data:\") {\n safe := strings.HasPrefix(val, \"data:image/png\") ||\n strings.HasPrefix(val, \"data:image/jpeg\") ||\n strings.HasPrefix(val, \"data:image/gif\") ||\n strings.HasPrefix(val, \"data:image/webp\")\n if !safe {\n continue\n }\n}\n```\n\nIf you prefer extending the blocklist, add at minimum: `text/xml`, `application/xml`, `text/xsl`, and `multipart/` types.", "title": "github - https://github.com/advisories/GHSA-4mx9-3c2h-hwhg" }, { "category": "description", "text": "# SanitizeSVG bypass via data:text/xml in getDynamicIcon (incomplete fix for CVE-2026-29183)\n\n`SanitizeSVG` blocks `data:text/html` and `data:image/svg+xml` in href attributes but misses `data:text/xml` and `data:application/xml`. Both render SVG with `onload` JavaScript execution (confirmed in Chromium 136, other browsers untested).\n\n`/api/icon/getDynamicIcon` is unauthenticated and serves SVG as `Content-Type: image/svg+xml`. The `content` parameter (type=8) gets embedded into the SVG via `fmt.Sprintf` with no escaping. The sanitizer catches `data:text/html` but `data:text/xml` passes the blocklist -- only three MIME types are checked.\n\nThis is a click-through XSS: victim visits the crafted URL, sees an SVG with an injected link, clicks it. If SiYuan renders these icons via `` tags in the frontend, links aren't interactive there -- the attack needs direct navigation to the endpoint URL or ``/`` embedding.\n\n## Steps to reproduce\n\nAgainst SiYuan v3.6.0 (Docker):\n\n```sh\n# 1. data:text/xml bypass -- element preserved with href intact\ncurl -s --get \"http://127.0.0.1:6806/api/icon/getDynamicIcon\" \\\n --data-urlencode 'type=8' \\\n --data-urlencode 'content=click' \\\n | grep -o ']*>'\n# Output: \n\n# 2. data:text/html is correctly blocked -- href stripped\ncurl -s --get \"http://127.0.0.1:6806/api/icon/getDynamicIcon\" \\\n --data-urlencode 'type=8' \\\n --data-urlencode 'content=alert(1)\">click' \\\n | grep -o ']*>'\n# Output: (href removed)\n\n# 3. data:application/xml also bypasses\ncurl -s --get \"http://127.0.0.1:6806/api/icon/getDynamicIcon\" \\\n --data-urlencode 'type=8' \\\n --data-urlencode 'content=click' \\\n | grep -o ']*>'\n# Output: (href preserved)\n```\n\nJS execution confirmed in Chromium 136 -- `data:text/xml` SVG `onload` fires and posts a message to the parent window via iframe test.\n\n## Vulnerable code\n\n`kernel/util/misc.go` lines 289-293:\n\n```go\nif strings.HasPrefix(val, \"data:\") {\n if strings.Contains(val, \"text/html\") || strings.Contains(val, \"image/svg+xml\") || strings.Contains(val, \"application/xhtml+xml\") {\n continue\n }\n}\n```\n\n`text/xml` and `application/xml` aren't in the list. Both serve SVG with JS execution.\n\n## Impact\n\nReflected XSS on an unauthenticated endpoint. Victim visits the crafted URL, then clicks the injected link in the SVG. No auth needed to craft the URL.\n\nDocker deployments where SiYuan is network-accessible are the clearest target -- the endpoint is reachable directly. In the Electron desktop app, impact depends on `nodeIntegration`/`contextIsolation` settings. Issue #15970 (\"XSS to RCE\") explored that path.\n\nThe deeper issue: the blocklist approach for data: URIs is fragile. `text/xml` and `application/xml` are the gap today, but other MIME types that render active content could surface. An allowlist of safe image types covers the known vectors and future MIME type additions.\n\n## Affected versions\n\nv3.6.0 (latest, confirmed). All versions since `SanitizeSVG` was added to fix CVE-2026-29183.\n\n## Suggested fix\n\nFlip the data: URI check to an allowlist -- only permit safe image types in href:\n\n```go\nif strings.HasPrefix(val, \"data:\") {\n safe := strings.HasPrefix(val, \"data:image/png\") ||\n strings.HasPrefix(val, \"data:image/jpeg\") ||\n strings.HasPrefix(val, \"data:image/gif\") ||\n strings.HasPrefix(val, \"data:image/webp\")\n if !safe {\n continue\n }\n}\n```\n\nIf you prefer extending the blocklist, add at minimum: `text/xml`, `application/xml`, `text/xsl`, and `multipart/` types.", "title": "github - https://api.github.com/advisories/GHSA-4mx9-3c2h-hwhg" }, { "category": "description", "text": "SiYuan is a personal knowledge management system. In versions 3.6.0 and below, SanitizeSVG has an incomplete blocklist — it blocks data:text/html and data:image/svg+xml in href attributes but misses data:text/xml and data:application/xml, both of which can render SVG with JavaScript execution. The unauthenticated /api/icon/getDynamicIcon endpoint serves user-controlled input (via the content parameter) directly into SVG markup using fmt.Sprintf with no escaping, served as Content-Type: image/svg+xml. This creates a click-through XSS: a victim navigates to a crafted URL, sees an SVG with an injected link, and clicking it triggers JavaScript via the bypassed MIME types. The attack requires direct navigation to the endpoint or / embedding, since tag rendering in the frontend doesn't allow interactive links. This issue has been fixed in version 3.6.1.", "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/32xxx/CVE-2026-32940.json" }, { "category": "description", "text": "SiYuan is a personal knowledge management system. In versions 3.6.0 and below, SanitizeSVG has an incomplete blocklist — it blocks data:text/html and data:image/svg+xml in href attributes but misses data:text/xml and data:application/xml, both of which can render SVG with JavaScript execution. The unauthenticated /api/icon/getDynamicIcon endpoint serves user-controlled input (via the content parameter) directly into SVG markup using fmt.Sprintf with no escaping, served as Content-Type: image/svg+xml. This creates a click-through XSS: a victim navigates to a crafted URL, sees an SVG with an injected link, and clicking it triggers JavaScript via the bypassed MIME types. The attack requires direct navigation to the endpoint or / embedding, since tag rendering in the frontend doesn't allow interactive links. This issue has been fixed in version 3.6.1.", "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-32940" }, { "category": "description", "text": "SiYuan has a SanitizeSVG bypass via data:text/xml in getDynamicIcon (incomplete fix for CVE-2026-29183) in github.com/siyuan-note/siyuan", "title": "osv - https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGO-2026-4721.json?alt=media" }, { "category": "description", "text": "# SanitizeSVG bypass via data:text/xml in getDynamicIcon (incomplete fix for CVE-2026-29183)\n\n`SanitizeSVG` blocks `data:text/html` and `data:image/svg+xml` in href attributes but misses `data:text/xml` and `data:application/xml`. Both render SVG with `onload` JavaScript execution (confirmed in Chromium 136, other browsers untested).\n\n`/api/icon/getDynamicIcon` is unauthenticated and serves SVG as `Content-Type: image/svg+xml`. The `content` parameter (type=8) gets embedded into the SVG via `fmt.Sprintf` with no escaping. The sanitizer catches `data:text/html` but `data:text/xml` passes the blocklist -- only three MIME types are checked.\n\nThis is a click-through XSS: victim visits the crafted URL, sees an SVG with an injected link, clicks it. If SiYuan renders these icons via `` tags in the frontend, links aren't interactive there -- the attack needs direct navigation to the endpoint URL or ``/`` embedding.\n\n## Steps to reproduce\n\nAgainst SiYuan v3.6.0 (Docker):\n\n```sh\n# 1. data:text/xml bypass -- element preserved with href intact\ncurl -s --get \"http://127.0.0.1:6806/api/icon/getDynamicIcon\" \\\n --data-urlencode 'type=8' \\\n --data-urlencode 'content=click' \\\n | grep -o ']*>'\n# Output: \n\n# 2. data:text/html is correctly blocked -- href stripped\ncurl -s --get \"http://127.0.0.1:6806/api/icon/getDynamicIcon\" \\\n --data-urlencode 'type=8' \\\n --data-urlencode 'content=alert(1)\">click' \\\n | grep -o ']*>'\n# Output: (href removed)\n\n# 3. data:application/xml also bypasses\ncurl -s --get \"http://127.0.0.1:6806/api/icon/getDynamicIcon\" \\\n --data-urlencode 'type=8' \\\n --data-urlencode 'content=click' \\\n | grep -o ']*>'\n# Output: (href preserved)\n```\n\nJS execution confirmed in Chromium 136 -- `data:text/xml` SVG `onload` fires and posts a message to the parent window via iframe test.\n\n## Vulnerable code\n\n`kernel/util/misc.go` lines 289-293:\n\n```go\nif strings.HasPrefix(val, \"data:\") {\n if strings.Contains(val, \"text/html\") || strings.Contains(val, \"image/svg+xml\") || strings.Contains(val, \"application/xhtml+xml\") {\n continue\n }\n}\n```\n\n`text/xml` and `application/xml` aren't in the list. Both serve SVG with JS execution.\n\n## Impact\n\nReflected XSS on an unauthenticated endpoint. Victim visits the crafted URL, then clicks the injected link in the SVG. No auth needed to craft the URL.\n\nDocker deployments where SiYuan is network-accessible are the clearest target -- the endpoint is reachable directly. In the Electron desktop app, impact depends on `nodeIntegration`/`contextIsolation` settings. Issue #15970 (\"XSS to RCE\") explored that path.\n\nThe deeper issue: the blocklist approach for data: URIs is fragile. `text/xml` and `application/xml` are the gap today, but other MIME types that render active content could surface. An allowlist of safe image types covers the known vectors and future MIME type additions.\n\n## Affected versions\n\nv3.6.0 (latest, confirmed). All versions since `SanitizeSVG` was added to fix CVE-2026-29183.\n\n## Suggested fix\n\nFlip the data: URI check to an allowlist -- only permit safe image types in href:\n\n```go\nif strings.HasPrefix(val, \"data:\") {\n safe := strings.HasPrefix(val, \"data:image/png\") ||\n strings.HasPrefix(val, \"data:image/jpeg\") ||\n strings.HasPrefix(val, \"data:image/gif\") ||\n strings.HasPrefix(val, \"data:image/webp\")\n if !safe {\n continue\n }\n}\n```\n\nIf you prefer extending the blocklist, add at minimum: `text/xml`, `application/xml`, `text/xsl`, and `multipart/` types.", "title": "osv - https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGHSA-4mx9-3c2h-hwhg.json?alt=media" }, { "category": "other", "text": "0.00048", "title": "EPSS" }, { "category": "other", "text": "3.7", "title": "NCSC Score" }, { "category": "other", "text": "There is exploit data available from source Nvd, Is related to (a version of) an uncommon product, Is related to an uncommon product vendor", "title": "NCSC Score top decreasing factors" } ], "product_status": { "known_affected": [ "CSAFPID-5825995", "CSAFPID-5839032", "CSAFPID-5920116" ] }, "references": [ { "category": "external", "summary": "Source - github", "url": "https://github.com/advisories/GHSA-4mx9-3c2h-hwhg" }, { "category": "external", "summary": "Source raw - github", "url": "https://api.github.com/advisories/GHSA-4mx9-3c2h-hwhg" }, { "category": "external", "summary": "Source - github", "url": "https://api.github.com/advisories/GHSA-4mx9-3c2h-hwhg" }, { "category": "external", "summary": "Source - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/32xxx/CVE-2026-32940.json" }, { "category": "external", "summary": "Source - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-32940" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Source - osv", "url": "https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGO-2026-4721.json?alt=media" }, { "category": "external", "summary": "Source - osv", "url": "https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGHSA-4mx9-3c2h-hwhg.json?alt=media" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd; osv", "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-4mx9-3c2h-hwhg" }, { "category": "external", "summary": "Reference - github", "url": "https://github.com/advisories/GHSA-4mx9-3c2h-hwhg" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd; osv", "url": "https://github.com/siyuan-note/siyuan/commit/d01d561875d4f744e9f6232f1d4831e3642b8696" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd; osv", "url": "https://github.com/advisories/GHSA-6865-qjcf-286f" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd; osv", "url": "https://github.com/siyuan-note/siyuan/releases/tag/v3.6.1" }, { "category": "external", "summary": "Reference - github; osv", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32940" } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N", "baseScore": 9.3, "baseSeverity": "CRITICAL" }, "products": [ "CSAFPID-5825995", "CSAFPID-5839032", "CSAFPID-5920116" ] } ], "title": "CVE-2026-32940" } ] }