---
cve: "CVE-2026-65902"
severity: "MEDIUM"
cvss: 5.3
epss: "21%"
vendor: "cure53"
kev: false
exploited: false
published: "2026-07-23 14:18:05"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-12T01:53:13+02:00"
---

# CVE-2026-65902

> 5.3 MEDIUM · 🧪 PoC

## Beschreibung

DOMPurify before 3.4.7 (affected versions <= 3.4.5) passes direct references to the module-level DEFAULT_ALLOWED_TAGS and DEFAULT_ALLOWED_ATTR sets to the uponSanitizeElement and uponSanitizeAttribute hooks via data.allowedTags / data.allowedAttributes when sanitize is called without an explicit cfg.ALLOWED_TAGS / cfg.ALLOWED_ATTR array. A hook that mutates these fields permanently widens the default allow-lists for the lifetime of the DOMPurify instance, so all subsequent default-config sanitize calls inherit the widened defaults and attacker payloads using the poisoned tag/attribute name survive sanitization. removeAllHooks(), clearConfig(), and passing a fresh cfg do not recover the state; only constructing a new DOMPurify instance does.

## 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)

- ca30f070c360df162a3e3848e80e6fd3c9e74bff (Commit)
- 7996f1dc78eb8b7922388aed75d94a9f8fad9a36 (Commit)

## Referenzen

- <https://github.com/cure53/DOMPurify/security/advisories/GHSA-76mc-f452-cxcm>
- <https://github.com/cure53/DOMPurify/commit/7996f1dc78eb8b7922388aed75d94a9f8fad9a36>
- <https://www.vulncheck.com/advisories/dompurify-before-hook-mutation-pollution-via-allowedtags>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-65902) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_