# CVE-2026-57530: Milkdown < 7.21.3 Stored XSS via javascript: URL in link href

> Attackers with document write access can execute arbitrary JavaScript in other users' browsers via malicious links in Milkdown documents.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/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:** A user has to click or open something
- **Fix available:** No
- **Published:** 24 Jul 2026
- **Updated:** 25 Jul 2026
- **Also known as:** GHSA-f8jw-52vm-m867

## What is CVE-2026-57530?

CVE-2026-57530 is a medium-severity cross-site scripting vulnerability in milkdown, published on 24 Jul 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

Milkdown before 7.21.3 contains a stored cross-site scripting vulnerability in the @milkdown/preset-commonmark and @milkdown/components packages that allows attackers with document write access to execute arbitrary JavaScript in the browser context of any user who opens the document or clicks a rendered link. The parseMarkdown runner stores raw URL values from the remark AST as href mark attributes without URL scheme validation, and the ineffective DOMPurify.sanitize call in edit-view.ts treats the bare URL string as a text node and returns it unchanged, allowing javascript: payloads to pass through the link-tooltip preview component and read-only mode anchor elements unmodified.

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

## Which versions are affected by CVE-2026-57530?


## How do I fix CVE-2026-57530?

No fix has been published for CVE-2026-57530 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-57530 being exploited?

There is no known exploitation of CVE-2026-57530 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57530 and fix it if it is affected.

What it is: CVE-2026-57530 is a medium-severity cross-site scripting vulnerability in milkdown, published on 24 Jul 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-2026-57530 in the wild and no public exploit code.

Affected product: milkdown. 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-2026-57530/ (Markdown: https://insights.sbomify.com/CVE-2026-57530/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57530
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57530
- OSV: https://osv.dev/vulnerability/CVE-2026-57530

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-57530/
Summaries are generated and may contain mistakes; the official description above is the record.