# CVE-2026-103687: rhukster dom-sanitizer SVG Sanitization DOMSanitizer.php url incomplete blacklist

> Attackers can bypass SVG sanitization via incomplete URL blacklisting to inject malicious scripts, requiring an upgrade to the dom-sanitizer library.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Oct 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-cjfg-j8jp-5xvc, GHSA-xpxw-4f4p-f3h2

## What is CVE-2026-103687?

CVE-2026-103687 is a medium-severity cross-site scripting vulnerability in rhukster dom-sanitizer, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability has been found in rhukster dom-sanitizer up to 1.0.15. The affected element is the function url of the file src/DOMSanitizer.php of the component SVG Sanitization. Such manipulation leads to incomplete blacklist. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 1.0.16 is sufficient to fix this issue. The name of the patch is 139c46c3d7c9bc81542b7b5a58d5cde5d0e0195a. Upgrading the affected component is recommended.

Weakness: CWE-184 (Incomplete List of Disallowed Inputs), CWE-183 (Permissive List of Allowed Inputs)

## Which versions are affected by CVE-2026-103687?


## How do I fix CVE-2026-103687?

No fix has been published for CVE-2026-103687 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-103687 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-103687 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103687 and fix it if it is affected.

What it is: CVE-2026-103687 is a medium-severity cross-site scripting vulnerability in rhukster dom-sanitizer, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-103687 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-2026-103687/ (Markdown: https://insights.sbomify.com/CVE-2026-103687/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103687
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103687
- OSV: https://osv.dev/vulnerability/CVE-2026-103687

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103687/
Summaries are generated and may contain mistakes; the official description above is the record.