# CVE-2026-100720: Froxlor before 2.3.12 Stored XSS via SSL certificate issuer

> Stored XSS in Froxlor allows customers to execute scripts in admin sessions via SSL certificate issuer fields, leading to account takeover and potential root code execution.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/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:** 26 Sep 2026
- **Updated:** 26 Sep 2026
- **Also known as:** GHSA-89vj-gqqr-73p8, GHSA-mmqp-fgp4-5q7j

## What is CVE-2026-100720?

CVE-2026-100720 is a critical cross-site scripting vulnerability in froxlor, published on 26 Sep 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

Froxlor 2.0.0 through 2.3.10 is vulnerable to stored cross-site scripting. When a customer (the lowest-privileged authenticated role) uploads an SSL certificate for one of their own domains, the Certificates API add()/update() methods parse it with openssl_x509_parse() and store the issuer organization (issuer['O']) value verbatim without sanitization. Froxlor's table-listing renderer then emits scalar cells through Twig's `raw` filter, disabling HTML auto-escaping, so when an administrator or reseller opens Domains > SSL certificates the attacker-supplied issuer value executes as script in the privileged user's session. This crosses a privilege boundary from customer to admin and can result in full administrator account takeover; because a Froxlor admin controls webserver, DNS, and PHP configuration applied by a cron job running as root, the issue can be further escalated to command execution as root on the managed server. The issue is fixed in Froxlor 2.3.12.

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

## Which versions are affected by CVE-2026-100720?


## How do I fix CVE-2026-100720?

No fix has been published for CVE-2026-100720 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-100720 being exploited?

There is no known exploitation of CVE-2026-100720 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100720 and fix it if it is affected.

What it is: CVE-2026-100720 is a critical cross-site scripting vulnerability in froxlor, published on 26 Sep 2026. 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-2026-100720 in the wild and no public exploit code.

Affected product: froxlor. 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-2026-100720/ (Markdown: https://insights.sbomify.com/CVE-2026-100720/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100720
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100720
- OSV: https://osv.dev/vulnerability/CVE-2026-100720

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-100720/
Summaries are generated and may contain mistakes; the official description above is the record.