{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-100639 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-100639 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-100639 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 26 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-100639 and fix it if it is affected.\n\nWhat it is: CVE-2026-100639 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 26 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-100639 in the wild and no public exploit code.\n\nAffected product: siyuan-note siyuan. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-100639/ (Markdown: https://insights.sbomify.com/CVE-2026-100639/index.md)","id":"CVE-2026-100639","markdown":"https://insights.sbomify.com/CVE-2026-100639/index.md","name":"CVE-2026-100639","record":{"aliases":["GHSA-2cmm-9x9j-rvff","GHSA-r9x8-34vf-7m8q"],"analysis":{"component_type":"desktop_application","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"SiYuan note-taking app","requires_auth":"none","summary":"An attacker can achieve remote code execution by tricking a victim into pasting malicious Markdown that triggers XSS in the Electron desktop application.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[],"cvss":{"score":8.6,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"SiYuan v3.8.3 fails to HTML-escape the data-subtype attribute when generating gutter-button markup (app/src/protyle/gutter/button.ts, assigned via innerHTML in app/src/protyle/gutter/index.ts) from content pasted as plain-text Markdown containing a Kramdown inline attribute list (IAL). Because the shared Lute renderer parses Kramdown IAL from text/plain input, an attacker-supplied Markdown snippet using entity-encoded quotes in data-subtype breaks out of the attribute value when the gutter markup is re-parsed by the browser, injecting additional attributes such as autofocus and onfocus. If a victim pastes the crafted Markdown and the affected gutter control receives focus, the injected handler executes; in the Electron desktop application, where the main BrowserWindow enables Node integration and disables context isolation, this results in JavaScript execution with renderer Node.js privileges (remote code execution). Fixed in v3.8.4.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"SiYuan before v3.8.4 Cross-Site Scripting via Kramdown IAL","id":"CVE-2026-100639","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"xss","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"SiYuan before v3.8.4 Clipboard Data Disclosure via IPC","id":"CVE-2026-100640"},"packages":[],"prev":{"headline":"SiYuan before v3.8.4 Path Traversal via setNotebookIcon","id":"CVE-2026-100638"},"products":["siyuan"],"published":"2026-09-26","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-09-28","vendors":["siyuan-note"]},"summary":"An attacker can achieve remote code execution by tricking a victim into pasting malicious Markdown that triggers XSS in the Electron desktop application.","url":"https://insights.sbomify.com/CVE-2026-100639/"}