# CVE-2026-58228: Scheme validation bypass in Phoenix.LiveView.Utils leads to XSS via <.link>

> Attackers can execute JavaScript in victim sessions by bypassing URL scheme validation in Phoenix LiveView links, affecting applications rendering user-supplied URLs.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:H/SI:H/SA: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:** 13 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** EEF-CVE-2026-58228, GHSA-5cgh-g58j-m9cq

## What is CVE-2026-58228?

CVE-2026-58228 is a medium-severity cross-site scripting vulnerability in phoenixframework phoenix_live_view, published on 13 Jul 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

Cross-site scripting vulnerability in phoenixframework phoenix_live_view allows an attacker to bypass URL scheme validation and execute JavaScript in a victim's browser session.

The Phoenix.LiveView.Utils.valid_destination!/2 and Phoenix.LiveView.Utils.valid_live_navigation_destination!/2 functions in lib/phoenix_live_view/utils.ex rely on an internal uri_scheme/1 helper that only detects a scheme when the input's first byte is an ASCII letter. Inputs beginning with an ASCII control character or space fall through to a nil-returning clause, causing the URL to be treated as a safe relative path.

Standard browsers implement the WHATWG URL parser, which strips leading C0 control and space characters before parsing. As a result, an input such as " javascript:alert(1)" is passed unchanged into <.link href={...}> and, when clicked, is parsed by the browser as a javascript: URL that executes attacker-controlled script in the victim's session.

Applications that render user-supplied URLs (for example profile links, redirect targets, or external references) via <.link href={...}> are affected.

This issue affects phoenix_live_view: from 1.2.2 before 1.2.7.

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

## Which versions are affected by CVE-2026-58228?

1 open source package ship an affected version, including phoenix_live_view.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `phoenix_live_view` | Hex | From 1.2.2 | 1.2.7 |

## How do I fix CVE-2026-58228?

Upgrade phoenix_live_view to 1.2.7 or later.

## Is CVE-2026-58228 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-58228 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-58228 and fix it if it is affected.

What it is: CVE-2026-58228 is a medium-severity cross-site scripting vulnerability in phoenixframework phoenix_live_view, published on 13 Jul 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-58228 exists.

Affected packages and fixed versions:
- phoenix_live_view (Hex): affected from 1.2.2; fixed in 1.2.7

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-2026-58228/ (Markdown: https://insights.sbomify.com/CVE-2026-58228/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-58228
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-58228
- OSV: https://osv.dev/vulnerability/CVE-2026-58228

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-58228/
Summaries are generated and may contain mistakes; the official description above is the record.