# CVE-2026-82654: SiYuan before v3.8.1 Stored XSS via block name

> Attackers can inject malicious scripts via block names that execute when other users view related documents in SiYuan.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 30 Aug 2026
- **Updated:** 1 Sep 2026
- **Also known as:** GHSA-5x6r-p3h7-38vj, GHSA-hf87-qh3j-3p88

## What is CVE-2026-82654?

CVE-2026-82654 is a critical cross-site scripting vulnerability in siyuan-note siyuan, published on 30 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

SiYuan before v3.8.1 fails to properly escape block name, alias, and memo fields in hint, backlink, and breadcrumb rendering functions. Attackers can set a block's name to contain HTML/script tags that execute when another user views documents referencing or displaying that block.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-82654?


## How do I fix CVE-2026-82654?

No fix has been published for CVE-2026-82654 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-82654 being exploited?

There is no known exploitation of CVE-2026-82654 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82654 and fix it if it is affected.

What it is: CVE-2026-82654 is a critical cross-site scripting vulnerability in siyuan-note siyuan, published on 30 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-82654 in the wild and no public exploit code.

Affected product: siyuan-note siyuan. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-82654/ (Markdown: https://insights.sbomify.com/CVE-2026-82654/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82654
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82654
- OSV: https://osv.dev/vulnerability/CVE-2026-82654

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82654/
Summaries are generated and may contain mistakes; the official description above is the record.