# CVE-2026-66353: Doggo vulnerable to cross-site scripting via unescaped date field values

> Reflected XSS in Doggo library allows attackers to inject scripts via date fields, potentially leading to code execution in web applications using the library.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/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:** 27 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** EEF-CVE-2026-66353, GHSA-w9rp-cf93-86pj

## What is CVE-2026-66353?

CVE-2026-66353 is a medium-severity cross-site scripting vulnerability in woylie doggo, published on 27 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

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in woylie doggo allows Reflected XSS.

Doggo.normalize_value/2 in lib/doggo.ex returned date field values wrapped in {:safe, ...}, the Phoenix.HTML marker meaning "already escaped, emit verbatim", without escaping them, so the value reached the value attribute of the <input> rendered by the field component unchanged. Any application rendering <.field type="date"> over user-controlled params is affected through the ordinary Phoenix form round-trip, where a failed validation re-renders the submitted value. The pattern kept exactly the first ten bytes and discarded shorter values, capping a payload at ten bytes: enough to terminate the attribute and open an element or attach a short event handler, not enough to place attacker-chosen script inline. Only type="date" is affected.

This issue affects doggo: from 0.1.0 before 0.14.8.

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

## Which versions are affected by CVE-2026-66353?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `doggo` | Hex | From 0.1.0 | 0.14.8 |

## How do I fix CVE-2026-66353?

Upgrade doggo to 0.14.8 or later.

## Is CVE-2026-66353 being exploited?

There is no known exploitation of CVE-2026-66353 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-66353 and fix it if it is affected.

What it is: CVE-2026-66353 is a medium-severity cross-site scripting vulnerability in woylie doggo, published on 27 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-2026-66353 in the wild and no public exploit code.

Affected packages and fixed versions:
- doggo (Hex): affected from 0.1.0; fixed in 0.14.8

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-2026-66353/ (Markdown: https://insights.sbomify.com/CVE-2026-66353/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-66353
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-66353
- OSV: https://osv.dev/vulnerability/CVE-2026-66353

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-66353/
Summaries are generated and may contain mistakes; the official description above is the record.