# CVE-2026-73490: Loofah: SVG `href` attribute bypasses local-reference restriction

> Attackers can bypass SVG sanitization restrictions to inject scripts or track users via external references in applications using Loofah.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 12 Aug 2026
- **Updated:** 13 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-73490, GHSA-9wjq-cp2p-hrgf, UBUNTU-CVE-2026-73490

## What is CVE-2026-73490?

CVE-2026-73490 is a medium-severity cross-site scripting vulnerability in flavorjones loofah, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. Prior to 2.25.2, Loofah's HTML5 sanitizer applies its local-reference restriction only to the xlink:href attribute on SVG use and feImage elements, while browsers also accept the plain href attribute. A crafted sanitized SVG can therefore reference an arbitrary same-origin external document; use may render external SVG content containing scripts or other dangerous content, and feImage may load external images for tracking. Applications that sanitize user-supplied SVG with Loofah's default allowlist are affected. This issue is fixed in version 2.25.2.

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

## Which versions are affected by CVE-2026-73490?

2 open source packages ship an affected version, including loofah.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `loofah` | RubyGems | All versions | 2.25.2 |
| `loofah` | RubyGems | All versions | 2.25.2 |

## How do I fix CVE-2026-73490?

Upgrade loofah to 2.25.2 or later.

## Is CVE-2026-73490 being exploited?

There is no known exploitation of CVE-2026-73490 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73490 and fix it if it is affected.

What it is: CVE-2026-73490 is a medium-severity cross-site scripting vulnerability in flavorjones loofah, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-73490 in the wild and no public exploit code.

Affected packages and fixed versions:
- loofah (RubyGems): affected all versions; fixed in 2.25.2
- loofah (RubyGems): affected all versions; fixed in 2.25.2

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-2026-73490/ (Markdown: https://insights.sbomify.com/CVE-2026-73490/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73490
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73490
- OSV: https://osv.dev/vulnerability/CVE-2026-73490

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73490/
Summaries are generated and may contain mistakes; the official description above is the record.