# CVE-2026-107380: enshrined/svg-sanitize: Stored XSS via DTD Entity / HTML5 Named Character Reference Collision

> Attackers can execute arbitrary JavaScript in the context of applications using this PHP SVG sanitizer by exploiting a collision between DTD entity expansion and HTML5 character reference resolution.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/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:** Yes
- **Published:** 8 Oct 2026
- **Updated:** 9 Oct 2026
- **Also known as:** GHSA-9rjx-3jch-6vjf

## What is CVE-2026-107380?

CVE-2026-107380 is a medium-severity cross-site scripting vulnerability in darylldoyle svg-sanitizer, published on 8 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

savg-sanitizer is a PHP SVG/XML sanitizer. Prior to 1.0.0, svg-sanitizer's isHrefSafeValue() validates an SVG href after XML DTD entity expansion, but saveXML() serializes the original entity reference after removing the DTD declaration. A crafted entity such as Tab can appear to the sanitizer as a safe fragment prefix while HTML5 Named Character Reference resolution during inline HTML rendering later converts the surviving reference to whitespace, exposing a javascript: URL. When an application embeds the sanitized SVG inline, a user who activates the link can cause script to execute in the embedding page's origin. This issue is fixed in version 1.0.0.

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

## Which versions are affected by CVE-2026-107380?

2 open source packages ship an affected version, including enshrined/svg-sanitize.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `enshrined/svg-sanitize` | Packagist | All versions | 1.0.0 |
| `enshrined/svg-sanitize` | Packagist | All versions | 1.0.0 |

## How do I fix CVE-2026-107380?

Upgrade enshrined/svg-sanitize to 1.0.0 or later.

## Is CVE-2026-107380 being exploited?

There is no known exploitation of CVE-2026-107380 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-107380 and fix it if it is affected.

What it is: CVE-2026-107380 is a medium-severity cross-site scripting vulnerability in darylldoyle svg-sanitizer, published on 8 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: There is no known exploitation of CVE-2026-107380 in the wild and no public exploit code.

Affected packages and fixed versions:
- enshrined/svg-sanitize (Packagist): affected all versions; fixed in 1.0.0
- enshrined/svg-sanitize (Packagist): affected all versions; fixed in 1.0.0

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-2026-107380/ (Markdown: https://insights.sbomify.com/CVE-2026-107380/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107380
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107380
- OSV: https://osv.dev/vulnerability/CVE-2026-107380

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-107380/
Summaries are generated and may contain mistakes; the official description above is the record.