# CVE-2026-34605: SiYuan: Reflected XSS via SVG namespace prefix bypass in SanitizeSVG ( getDynamicIcon, unauthenticated ) > An attacker can execute arbitrary JavaScript in a victim's browser via a reflected XSS vulnerability in the unauthenticated dynamic icon endpoint. - **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA: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:** 31 Mar 2026 - **Updated:** 1 Apr 2026 - **Also known as:** GHSA-73g7-86qr-jrg3, GO-2026-5201 ## What is CVE-2026-34605? CVE-2026-34605 is a high-severity cross-site scripting vulnerability in B3log Siyuan, published on 31 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. From version 3.6.0 to before version 3.6.2, the SanitizeSVG function introduced in version 3.6.0 to fix XSS in the unauthenticated /api/icon/getDynamicIcon endpoint can be bypassed by using namespace-prefixed element names such as . The Go HTML5 parser records the element's tag as "x:script" rather than "script", so the tag check passes it through. The SVG is served with Content-Type: image/svg+xml and no Content Security Policy; when a browser opens the response directly, its XML parser resolves the prefix to the SVG namespace and executes the embedded script. This issue has been patched in version 3.6.2. Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation) ## Which versions are affected by CVE-2026-34605? 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 | 0.0.0-20260330031106-f09953afc57a | | `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260330031106-f09953afc57a | | `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260330031106-f09953afc57a | Products: B3log Siyuan. ## How do I fix CVE-2026-34605? Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260330031106-f09953afc57a or later. ## Is CVE-2026-34605 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34605 exists. Public exploit code: - SiYuan Note - Cross-Site Scripting (nuclei): http/cves/2026/CVE-2026-34605.yaml ## 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-2026-34605 and fix it if it is affected. What it is: CVE-2026-34605 is a high-severity cross-site scripting vulnerability in B3log Siyuan, published on 31 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-2026-34605 exists. Affected packages and fixed versions: - github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260330031106-f09953afc57a - github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260330031106-f09953afc57a - github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260330031106-f09953afc57a 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-2026-34605/ (Markdown: https://insights.sbomify.com/CVE-2026-34605/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34605 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34605 - OSV: https://osv.dev/vulnerability/CVE-2026-34605 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-34605/ Summaries are generated and may contain mistakes; the official description above is the record.