# CVE-2026-57531: Milkdown < 7.21.3 DOM XSS via innerHTML Assignment

> Attackers can execute arbitrary JavaScript in the host application by tricking users into pasting malicious emoji content, affecting Milkdown users.

- **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-7jff-jg2j-4x95

## What is CVE-2026-57531?

CVE-2026-57531 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 DOM cross-site scripting vulnerability in the @milkdown/plugin-emoji package that allows unauthenticated attackers to execute arbitrary JavaScript in the host application's origin by causing a victim to paste attacker-controlled content. The parseDOM.getAttrs handler stores raw innerHTML of pasted span elements with data-type="emoji" without sanitization, and the toMarkdown runner subsequently assigns this unsanitized value directly to a live DOM element's innerHTML, bypassing the DOMPurify sanitization used in the toDOM path, causing payload execution on every markdown serialization cycle.

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

## Which versions are affected by CVE-2026-57531?


## How do I fix CVE-2026-57531?

No fix has been published for CVE-2026-57531 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-57531 being exploited?

There is no known exploitation of CVE-2026-57531 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57531 and fix it if it is affected.

What it is: CVE-2026-57531 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-2026-57531 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-2026-57531/ (Markdown: https://insights.sbomify.com/CVE-2026-57531/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57531
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57531
- OSV: https://osv.dev/vulnerability/CVE-2026-57531

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57531/
Summaries are generated and may contain mistakes; the official description above is the record.