{"id":"CVE-2026-75916","aliases":["EUVD-2026-62441","GHSA-5prr-vgxq-69g9","GHSA-962c-hgx6-ffmx"],"status":"published","title":"SiYuan XSS-to-RCE via unescaped block metadata in hint popup","description":"SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block's name, alias, and memo fields are concatenated into the popup's HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. \u003cimg src=x onerror=...\u003e) that executes automatically when a victim types '((' followed by a search term that surfaces the crafted block. Because SiYuan's Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require('child_process') access, allowing the XSS to escalate to arbitrary OS command execution.","severity":{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00225,"percentile":0.13338,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-08-19T14:01:50Z","modified":"2026-10-28T02:31:14Z","products":[{"vendor":"siyuan-note","product":"siyuan"}],"references":[{"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-5prr-vgxq-69g9","tags":["vendor-advisory","exploit","advisory"]},{"url":"https://www.vulncheck.com/advisories/siyuan-xss-to-rce-via-unescaped-block-metadata-in-hint-popup","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-75916","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-962c-hgx6-ffmx"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75916.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-75916","title":"SiYuan XSS-to-RCE via unescaped block metadata in hint popup","description":"SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block's name, alias, and memo fields are concatenated into the popup's HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. \u003cimg src=x onerror=...\u003e) that executes automatically when a victim types '((' followed by a search term that surfaces the crafted block. Because SiYuan's Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require('child_process') access, allowing the XSS to escalate to arbitrary OS command execution.","status":"published","published":"2026-08-19T14:01:50.37Z","modified":"2026-10-08T15:51:43.765Z","cvss":[{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"critical","assessor":"cna"},{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:20:07.260654Z"}],"euvd":[{"id":"EUVD-2026-62441","description":"SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block's name, alias, and memo fields are concatenated into the popup's HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. \u003cimg src=x onerror=...\u003e) that executes automatically when a victim types '((' followed by a search term that surfaces the crafted block. Because SiYuan's Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require('child_process') access, allowing the XSS to escalate to arbitrary OS command execution.","status":"published","published":"2026-08-19T14:01:50Z","modified":"2026-10-08T15:51:43Z","cvss":[{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"critical"}],"updated_at":"2026-11-02T17:27:28.564399Z"}],"ghsa":[{"id":"GHSA-962c-hgx6-ffmx","title":"SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference...","description":"SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block's name, alias, and memo fields are concatenated into the popup's HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. \u003cimg src=x onerror=...\u003e) that executes automatically when a victim types '((' followed by a search term that surfaces the crafted block. Because SiYuan's Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require('child_process') access, allowing the XSS to escalate to arbitrary OS command execution.","status":"published","published":"2026-08-19T15:32:28Z","modified":"2026-08-19T15:32:34Z","cvss":[{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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","level":"critical"},{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:10:39.892418Z"}],"nvd":[{"id":"CVE-2026-75916","description":"SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block's name, alias, and memo fields are concatenated into the popup's HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. \u003cimg src=x onerror=...\u003e) that executes automatically when a victim types '((' followed by a search term that surfaces the crafted block. Because SiYuan's Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require('child_process') access, allowing the XSS to escalate to arbitrary OS command execution.","status":"published","published":"2026-08-19T14:17:41.687Z","modified":"2026-10-08T16:17:41.53Z","cvss":[{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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","level":"critical","assessor":"secondary"},{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:39.620837Z"}],"osv":[{"id":"CVE-2026-75916","title":"SiYuan XSS-to-RCE via unescaped block metadata in hint popup","description":"SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block's name, alias, and memo fields are concatenated into the popup's HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. \u003cimg src=x onerror=...\u003e) that executes automatically when a victim types '((' followed by a search term that surfaces the crafted block. Because SiYuan's Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require('child_process') access, allowing the XSS to escalate to arbitrary OS command execution.","status":"published","published":"2026-08-19T14:01:50.37Z","modified":"2026-10-28T02:31:14.440497026Z","cvss":[{"version":"4.0","score":9.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"critical"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:17.102988Z"}]}}