# CVE-2026-87812: SiYuan before v3.8.2 Stored XSS via Bazaar iconURL

> Attackers can inject malicious JavaScript via Bazaar package icons, allowing code execution and state manipulation in SiYuan.

- **Severity:** High 7.4 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/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:** No
- **Published:** 9 Sep 2026
- **Updated:** 10 Sep 2026
- **Also known as:** GHSA-rv6c-xvcj-4qwg, GHSA-rvcf-q4h8-w6c9

## What is CVE-2026-87812?

CVE-2026-87812 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 9 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.

### Official description

SiYuan before v3.8.2 contains a stored cross-site scripting vulnerability in Bazaar package cards where the iconURL metadata is inserted directly into HTML img src attributes without escaping. Attackers can inject malicious URLs with event handlers that execute JavaScript in the authenticated SiYuan origin when users view Bazaar listings, enabling API requests and application state manipulation.

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

## Which versions are affected by CVE-2026-87812?


## How do I fix CVE-2026-87812?

No fix has been published for CVE-2026-87812 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-87812 being exploited?

There is no known exploitation of CVE-2026-87812 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-87812 and fix it if it is affected.

What it is: CVE-2026-87812 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 9 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.
Exploitation: There is no known exploitation of CVE-2026-87812 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-2026-87812/ (Markdown: https://insights.sbomify.com/CVE-2026-87812/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-87812
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-87812
- OSV: https://osv.dev/vulnerability/CVE-2026-87812

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-87812/
Summaries are generated and may contain mistakes; the official description above is the record.