# CVE-2026-88903: Topcontent <= 1.2.1 - Unauthenticated Stored XSS via Content Webhook

> Unauthenticated attackers can inject malicious JavaScript into posts via webhook if the plugin's API key is unconfigured, leading to stored XSS.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **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:** 11 Oct 2026
- **Updated:** 11 Oct 2026
- **Also known as:** GHSA-vrpv-vc9c-j35f

## What is CVE-2026-88903?

CVE-2026-88903 is a high-severity cross-site scripting vulnerability in Unknown Topcontent, published on 11 Oct 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

The Topcontent WordPress plugin through 1.2.1 does not properly authorise one of its request handlers and disables HTML sanitisation before storing the submitted content, allowing unauthenticated attackers to publish arbitrary posts containing malicious JavaScript on any site where its API key has never been configured.

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

## Which versions are affected by CVE-2026-88903?


## How do I fix CVE-2026-88903?

No fix has been published for CVE-2026-88903 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-88903 being exploited?

There is no known exploitation of CVE-2026-88903 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-88903 and fix it if it is affected.

What it is: CVE-2026-88903 is a high-severity cross-site scripting vulnerability in Unknown Topcontent, published on 11 Oct 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-2026-88903 in the wild and no public exploit code.

Affected product: Unknown Topcontent. 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-2026-88903/ (Markdown: https://insights.sbomify.com/CVE-2026-88903/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-88903
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88903
- OSV: https://osv.dev/vulnerability/CVE-2026-88903

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-88903/
Summaries are generated and may contain mistakes; the official description above is the record.