# CVE-2026-88976: @platejs/core HTML deserialization can trigger browser behavior during parsing

> Attackers can execute arbitrary scripts in the victim's browser by supplying malicious HTML to the Plate editor's deserialization APIs.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A: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:** 16 Sep 2026
- **Updated:** 16 Sep 2026
- **Also known as:** GHSA-qrfj-mgw8-j9c6

## What is CVE-2026-88976?

CVE-2026-88976 is a medium-severity cross-site scripting vulnerability in udecode plate, published on 16 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

Plate is a rich-text editor with AI and shadcn/ui. Prior to 53.3.11, and in the discontinued 54.0.0-beta.0 through 54.0.0-beta.1 builds, Plate core HTML deserialization APIs parse supplied HTML strings in the active document. When an application passes untrusted or cross-user HTML to these APIs, certain HTML attributes can trigger browser behavior before the HTML is converted into editor nodes. This can allow attacker-controlled script to execute in the consuming application's origin when another user loads the deserialized content. This issue is fixed in version 53.3.11.

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

## Which versions are affected by CVE-2026-88976?

4 open source packages ship an affected version, including @platejs/core.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@platejs/core` | npm | All versions | 53.3.11 |
| `@platejs/core` | npm | All versions | 53.3.11 |
| `@platejs/core` | npm | From 54.0.0-beta.0 to 54.0.0-beta.1 | None |
| `@platejs/core` | npm | From 54.0.0-beta.0 to 54.0.0-beta.1 | None |

## How do I fix CVE-2026-88976?

Upgrade @platejs/core to 53.3.11 or later.

## Is CVE-2026-88976 being exploited?

There is no known exploitation of CVE-2026-88976 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-88976 and fix it if it is affected.

What it is: CVE-2026-88976 is a medium-severity cross-site scripting vulnerability in udecode plate, published on 16 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-2026-88976 in the wild and no public exploit code.

Affected packages and fixed versions:
- @platejs/core (npm): affected all versions; fixed in 53.3.11
- @platejs/core (npm): affected all versions; fixed in 53.3.11
- @platejs/core (npm): affected from 54.0.0-beta.0 up to 54.0.0-beta.1; no fix listed
- @platejs/core (npm): affected from 54.0.0-beta.0 up to 54.0.0-beta.1; no fix listed

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-2026-88976/ (Markdown: https://insights.sbomify.com/CVE-2026-88976/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-88976
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88976
- OSV: https://osv.dev/vulnerability/CVE-2026-88976

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-88976/
Summaries are generated and may contain mistakes; the official description above is the record.