# CVE-2021-47931: Exponent CMS 2.6 Multiple Vulnerabilities Stored XSS Authentication

> Authenticated attackers can inject malicious scripts via text editing parameters in Exponent CMS, leading to arbitrary JavaScript execution and potential data exposure.

- **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:** 10 May 2026
- **Updated:** 26 May 2026
- **Also known as:** GHSA-6jxm-mv8c-gh34

## What is CVE-2021-47931?

CVE-2021-47931 is a medium-severity cross-site scripting vulnerability in Exponentcms Exponent CMS, published on 10 May 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

Exponent CMS 2.6 contains a stored cross-site scripting vulnerability that allows authenticated attackers to inject malicious scripts through the Title and Text Block parameters in the text editing endpoint. Attackers can inject iframe payloads with embedded SVG onload events to execute arbitrary JavaScript. The application also exposes database credentials in responses and lacks brute-force protection on authentication endpoints.

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

## Which versions are affected by CVE-2021-47931?


## How do I fix CVE-2021-47931?

No fix has been published for CVE-2021-47931 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47931 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47931 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47931 and fix it if it is affected.

What it is: CVE-2021-47931 is a medium-severity cross-site scripting vulnerability in Exponentcms Exponent CMS, published on 10 May 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47931 exists.

Affected product: Exponentcms Exponent CMS. 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-2021-47931/ (Markdown: https://insights.sbomify.com/CVE-2021-47931/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47931
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47931
- OSV: https://osv.dev/vulnerability/CVE-2021-47931

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-47931/
Summaries are generated and may contain mistakes; the official description above is the record.