---
cve: "CVE-2026-59729"
severity: "MEDIUM"
cvss: 5.1
epss: "0.5%"
vendor: "withastro"
kev: false
exploited: false
published: "2026-07-27 20:16:40"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-11-08T13:35:47+01:00"
---

# CVE-2026-59729

> 5.1 MEDIUM · 🧪 PoC

## Beschreibung

Astro is a web framework for content-driven websites. Versions prior to 7.0.6 are vulnerable to XSS through unescaped spread attribute names in renderHTMLElement. The fix for CVE-2026-54298 (GHSA-jrpj-wcv7-9fh9) added an INVALID_ATTR_NAME_CHAR guard to addAttribute() so that spread-prop attribute names containing "' >/= or whitespace are dropped. A second attribute-rendering path, renderHTMLElement() in packages/astro/src/runtime/server/render/dom.ts, has its own inline attribute loop that does not go through addAttribute() and was not updated. It interpolates the attribute name unescaped and only escapes the value, so untrusted prop keys spread onto a native-HTMLElement-subclass component can still break out of the attribute context. This issue has been fixed in version 7.0.6.

## CNA-Record (Kanon, cvelistV5)

- CNA: **GitHub_M**
- State: PUBLISHED
- Stand: 2026-07-28 13:48:46
- CNA-CVSS: **5.1** (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |

## Schwachstellen-Klasse

- **CWE-79** — Improper Neutralization of Input During Web Page Generation
  The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

## Angriffsmuster (CAPEC)

- [CAPEC-63 — Cross-Site Scripting (XSS)](https://capec.mitre.org/data/definitions/63.html) _(Severity: Very High)_
- [CAPEC-85 — AJAX Footprinting](https://capec.mitre.org/data/definitions/85.html) _(Severity: Low)_
- [CAPEC-209 — XSS Using MIME Type Mismatch](https://capec.mitre.org/data/definitions/209.html) _(Severity: Medium)_
- [CAPEC-588 — DOM-Based XSS](https://capec.mitre.org/data/definitions/588.html) _(Severity: Very High)_
- [CAPEC-591 — Reflected XSS](https://capec.mitre.org/data/definitions/591.html) _(Severity: Very High)_
- [CAPEC-592 — Stored XSS](https://capec.mitre.org/data/definitions/592.html) _(Severity: Very High)_

## Patch verfügbar (OSV)

- a86160ee79e4600bf77f89eb2dc84782acdeab6f (Commit)
- 5240e26c9dd91f9bc7140dcfacdb48d5a132830d (Commit)

## Referenzen

- <https://github.com/withastro/astro/security/advisories/GHSA-f48w-9m4c-m7f5>
- <https://github.com/withastro/astro/pull/17251>
- <https://github.com/withastro/astro/commit/5240e26c9dd91f9bc7140dcfacdb48d5a132830d>
- <https://github.com/withastro/astro/releases/tag/astro@7.0.6>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-59729/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_