# CVE-2026-33066: SiYuan has Stored XSS to RCE via Unsanitized Bazaar README Rendering > A stored XSS vulnerability in SiYuan allows malicious package authors to execute arbitrary code via unsanitized README rendering in the Electron app. - **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 20 Mar 2026 - **Updated:** 20 Mar 2026 - **Also known as:** GHSA-4663-4mpg-879v, GO-2026-4743 ## What is CVE-2026-33066? CVE-2026-33066 is a medium-severity cross-site scripting vulnerability in B3log Siyuan, published on 20 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description SiYuan is a personal knowledge management system. In versions 3.6.0 and below, the backend renderREADME function uses lute.New() without calling SetSanitize(true), allowing raw HTML embedded in Markdown to pass through unmodified. The frontend then assigns the rendered HTML to innerHTML without any additional sanitization. A malicious package author can embed arbitrary JavaScript in their README that executes when a user clicks to view the package details. Because SiYuan's Electron configuration enables nodeIntegration: true with contextIsolation: false, this XSS escalates directly to full Remote Code Execution. The issue was patched in version 3.6.1. Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation) ## Which versions are affected by CVE-2026-33066? 3 open source packages ship an affected version, including github.com/siyuan-note/siyuan/kernel. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260314111550-b382f50e1880 | | `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260314111550-b382f50e1880 | | `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260314111550-b382f50e1880 | Products: B3log Siyuan. ## How do I fix CVE-2026-33066? Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260314111550-b382f50e1880 or later. ## Is CVE-2026-33066 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33066 exists. ## Other vulnerabilities in B3log Siyuan - [CVE-2026-32938](https://insights.sbomify.com/CVE-2026-32938/): SiYuan has an Arbitrary File Read in its Desktop Publish Service (critical 9.9) - [CVE-2026-33669](https://insights.sbomify.com/CVE-2026-33669/): SiYuan has Arbitrary Document Reading within the Publishing Service (critical 9.8) - [CVE-2026-33670](https://insights.sbomify.com/CVE-2026-33670/): SiYuan has directory traversal within its publishing service (critical 9.8) - [CVE-2026-32767](https://insights.sbomify.com/CVE-2026-32767/): SiYuan: Authorization Bypass Allows Arbitrary SQL Execution via Search API (critical 9.8) - [CVE-2024-53504](https://insights.sbomify.com/CVE-2024-53504/): SQL injection in n/a (critical 9.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-33066 and fix it if it is affected. What it is: CVE-2026-33066 is a medium-severity cross-site scripting vulnerability in B3log Siyuan, published on 20 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33066 exists. Affected packages and fixed versions: - github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260314111550-b382f50e1880 - github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260314111550-b382f50e1880 - github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260314111550-b382f50e1880 Task: 1. 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. 2. 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. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-33066/ (Markdown: https://insights.sbomify.com/CVE-2026-33066/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33066 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33066 - OSV: https://osv.dev/vulnerability/CVE-2026-33066 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-33066/ Summaries are generated and may contain mistakes; the official description above is the record.