# CVE-2026-21618: Cross-site scripting (XSS) in OAuth Device Authorization screen

> An attacker can inject malicious scripts into the OAuth Device Authorization screen, potentially compromising user sessions or executing code in the victim's browser.

- **Severity:** High 8.5 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:L/SI:L/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:** No
- **Published:** 19 Jan 2026
- **Updated:** 24 Jul 2026
- **Also known as:** EEF-CVE-2026-21618, GHSA-6cw9-5gg4-rhpj

## What is CVE-2026-21618?

CVE-2026-21618 is a high-severity cross-site scripting vulnerability in hexpm hex.pm, published on 19 Jan 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

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in hexpm hexpm/hexpm ('Elixir.HexpmWeb.SharedAuthorizationView' modules) allows Cross-Site Scripting (XSS). This vulnerability is associated with program files lib/hexpm_web/views/shared_authorization_view.ex and program routines 'Elixir.HexpmWeb.SharedAuthorizationView':render_grouped_scopes/3.

This issue affects hexpm: from 617e44c71f1dd9043870205f371d375c5c4d886d before c692438684ead90c3bcbfb9ccf4e63c768c668a8; hex.pm: from 2025-10-01 before 2026-01-19.

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

## Which versions are affected by CVE-2026-21618?

It affects 1 product.


Products: Hex Hexpm.

## How do I fix CVE-2026-21618?

No fix has been published for CVE-2026-21618 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-21618 being exploited?

There is no known exploitation of CVE-2026-21618 in the wild and no public exploit code.

## Other vulnerabilities in hexpm hex.pm

- [CVE-2026-21622](https://insights.sbomify.com/CVE-2026-21622/): Password Reset Tokens Do Not Expire (critical 9.5)
- [CVE-2026-23940](https://insights.sbomify.com/CVE-2026-23940/): Denial of Service via Oversized Package Upload (high 7.1)
- [CVE-2026-21621](https://insights.sbomify.com/CVE-2026-21621/): Improper Scope Enforcement in OAuth client_credentials Flow Allows Read-Only API Key to Escalate to Full Access (high 7.0)
- [CVE-2026-23939](https://insights.sbomify.com/CVE-2026-23939/): Path Traversal in Local File Store Backend (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21618 and fix it if it is affected.

What it is: CVE-2026-21618 is a high-severity cross-site scripting vulnerability in hexpm hex.pm, published on 19 Jan 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-2026-21618 in the wild and no public exploit code.

Affected product: hexpm hex.pm. 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-2026-21618/ (Markdown: https://insights.sbomify.com/CVE-2026-21618/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21618
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21618
- OSV: https://osv.dev/vulnerability/CVE-2026-21618

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-21618/
Summaries are generated and may contain mistakes; the official description above is the record.