# CVE-2026-32940: SiYuan has a SanitizeSVG bypass via data:text/xml in getDynamicIcon (incomplete fix for CVE-2026-29183) > An attacker can execute arbitrary JavaScript in a victim's browser via a crafted URL due to an incomplete SVG sanitization bypass in SiYuan. - **Severity:** Critical 9.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 20 Mar 2026 - **Updated:** 20 Mar 2026 - **Also known as:** GHSA-4mx9-3c2h-hwhg, GO-2026-4721 ## What is CVE-2026-32940? CVE-2026-32940 is a critical cross-site scripting vulnerability in B3log Siyuan, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. ### Official description 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. Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-184 (Incomplete List of Disallowed Inputs) ## Which versions are affected by CVE-2026-32940? 3 open source packages ship an affected version, including github.com/siyuan-note/siyuan. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/siyuan-note/siyuan` | Go | All versions | None | | `github.com/siyuan-note/siyuan` | Go | All versions to 0.0.0-20260313024916-fd6526133bb3 | None | | `github.com/siyuan-note/siyuan` | Go | All versions to 0.0.0-20260313024916-fd6526133bb3 | None | Products: B3log Siyuan. ## How do I fix CVE-2026-32940? Upgrade to a fixed version. ## Is CVE-2026-32940 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32940 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-2026-32940 and fix it if it is affected. What it is: CVE-2026-32940 is a critical cross-site scripting vulnerability in B3log Siyuan, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32940 exists. Affected packages and fixed versions: - github.com/siyuan-note/siyuan (Go): affected all versions; no fix listed - github.com/siyuan-note/siyuan (Go): affected all versions up to 0.0.0-20260313024916-fd6526133bb3; no fix listed - github.com/siyuan-note/siyuan (Go): affected all versions up to 0.0.0-20260313024916-fd6526133bb3; no fix listed 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-2026-32940/ (Markdown: https://insights.sbomify.com/CVE-2026-32940/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32940 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32940 - OSV: https://osv.dev/vulnerability/CVE-2026-32940 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-32940/ Summaries are generated and may contain mistakes; the official description above is the record.