# CVE-2026-40508: OpenEMR < 8.3.0 Stored XSS via Patient Portal Template Import Handler

> Authenticated attackers with Forms Administration permissions can inject malicious scripts via template imports, leading to stored XSS execution in other administrators' browsers.

- **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:** 19 Aug 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-5293-8q47-cf44, GHSA-xvw4-236w-442q

## What is CVE-2026-40508?

CVE-2026-40508 is a medium-severity cross-site scripting vulnerability in openemr, published on 19 Aug 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

OpenEMR before 8.3.0 contains a stored cross-site scripting vulnerability in the patient portal template import handler that allows authenticated attackers with Forms Administration permissions to upload template files containing arbitrary HTML or JavaScript. Attackers can inject malicious scripts through the template upload functionality, which are stored without sanitization and execute in the browser of any other Forms Administration user who views the template in the HTML editor.

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

## Which versions are affected by CVE-2026-40508?


## How do I fix CVE-2026-40508?

No fix has been published for CVE-2026-40508 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-40508 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40508 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40508 and fix it if it is affected.

What it is: CVE-2026-40508 is a medium-severity cross-site scripting vulnerability in openemr, published on 19 Aug 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-2026-40508 exists.

Affected product: openemr. 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-2026-40508/ (Markdown: https://insights.sbomify.com/CVE-2026-40508/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40508
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40508
- OSV: https://osv.dev/vulnerability/CVE-2026-40508

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40508/
Summaries are generated and may contain mistakes; the official description above is the record.