---
cve: "CVE-2026-59710"
severity: "MEDIUM"
cvss: 5.3
epss: "20%"
vendor: "showdown"
kev: false
exploited: false
published: "2026-07-06 22:16:50"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-11T16:31:19+02:00"
---

# CVE-2026-59710

> 5.3 MEDIUM · 🧪 PoC

## Beschreibung

showdown contains a stored cross-site scripting vulnerability in the parseHeaders function of src/subParsers/makehtml/tables.js that fails to properly escape table header ID attributes. Attackers can inject arbitrary HTML and script-executing SVG elements through double-quote characters in markdown table headers, achieving stored XSS when untrusted markdown is rendered with the default github flavor configuration.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- e5cab1e9a5dcea2bb3cbf888863fa7e65ab37edf (Commit)

## Referenzen

- <https://github.com/showdownjs/showdown/issues/1046>
- <https://github.com/showdownjs/showdown>
- <https://github.com/showdownjs/showdown/commit/e5cab1e9a5dcea2bb3cbf888863fa7e65ab37edf>
- <https://www.vulncheck.com/advisories/showdown-stored-xss-via-unescaped-table-header-id-attribute-injection>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-59710) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_