# CVE-2025-66554: Nextcloud Contacts vulnerable to Stored XSS in contacts app via organisation and title field

> A malicious user can inject CSS via contact fields, bypassing some protections, requiring Nextcloud administrators to upgrade the Contacts app.

- **Severity:** Low 3.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A: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:** 5 Dec 2025
- **Updated:** 8 Dec 2025
- **Also known as:** GHSA-9v78-cpfc-v6h2

## What is CVE-2025-66554?

CVE-2025-66554 is a low-severity cross-site scripting vulnerability in nextcloud security-advisories, published on 5 Dec 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Contacts app for Nextcloud easily syncs contacts from various devices with your Nextcloud and allows editing. Prior to 5.5.4, 6.0.6, and 7.2.5, a malicious user was able to modify their organisation and title field to load additional CSS files. Javascript and other options were correctly blocked by the content security policy of the Nextcloud Server code. This vulnerability is fixed in 5.5.4, 6.0.6, and 7.2.5.

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

## Which versions are affected by CVE-2025-66554?

It affects 1 product.


Products: Nextcloud Contacts.

## How do I fix CVE-2025-66554?

No fix has been published for CVE-2025-66554 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-66554 being exploited?

There is no known exploitation of CVE-2025-66554 in the wild and no public exploit code.

## Other vulnerabilities in nextcloud security-advisories

- [CVE-2021-39221](https://insights.sbomify.com/CVE-2021-39221/): XSS in Contacts (medium 6.4)
- [CVE-2020-8280](https://insights.sbomify.com/CVE-2020-8280/): Cross-site scripting in Nextcloud Contacts (medium 5.4)
- [CVE-2020-8281](https://insights.sbomify.com/CVE-2020-8281/): Cross-site scripting in Nextcloud Contacts (medium 5.4)
- [CVE-2018-3764](https://insights.sbomify.com/CVE-2018-3764/): Cross-site scripting in Nextcloud Contacts application (medium 4.8)
- [CVE-2020-8181](https://insights.sbomify.com/CVE-2020-8181/): File upload in Nextcloud Contact (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-66554 and fix it if it is affected.

What it is: CVE-2025-66554 is a low-severity cross-site scripting vulnerability in nextcloud security-advisories, published on 5 Dec 2025. 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-2025-66554 in the wild and no public exploit code.

Affected product: nextcloud security-advisories. 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-2025-66554/ (Markdown: https://insights.sbomify.com/CVE-2025-66554/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-66554
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-66554
- OSV: https://osv.dev/vulnerability/CVE-2025-66554

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-66554/
Summaries are generated and may contain mistakes; the official description above is the record.