# CVE-2026-103686: rhukster dom-sanitizer URL Validation DOMSanitizer.php isDangerousUrl cross site scripting

> Remote attackers can execute arbitrary scripts via a flaw in URL validation within the rhukster dom-sanitizer library.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P`)
- **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:** 1 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** GHSA-mrpv-6x26-mf6c, GHSA-qjw9-86r9-fqqc

## What is CVE-2026-103686?

CVE-2026-103686 is a medium-severity cross-site scripting vulnerability in rhukster dom-sanitizer, published on 1 Oct 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

A flaw has been found in rhukster dom-sanitizer up to 1.0.15. Impacted is the function DOMSanitizer::isDangerousUrl of the file src/DOMSanitizer.php of the component URL Validation. This manipulation causes cross site scripting. It is possible to initiate the attack remotely. The exploit has been published and may be used. Upgrading to version 1.0.16 is recommended to address this issue. Patch name: 4623b565d060bc02ca5a07d8c8241fe28e2edfda. It is suggested to upgrade the affected component.

Weakness: CWE-94 (Improper Control of Generation of Code), CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-103686?


## How do I fix CVE-2026-103686?

No fix has been published for CVE-2026-103686 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-103686 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-103686 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103686 and fix it if it is affected.

What it is: CVE-2026-103686 is a medium-severity cross-site scripting vulnerability in rhukster dom-sanitizer, published on 1 Oct 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-2026-103686 exists.

Affected product: rhukster dom-sanitizer. 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-2026-103686/ (Markdown: https://insights.sbomify.com/CVE-2026-103686/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103686
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103686
- OSV: https://osv.dev/vulnerability/CVE-2026-103686

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103686/
Summaries are generated and may contain mistakes; the official description above is the record.