---
cve: "CVE-2026-25896"
severity: "CRITICAL"
cvss: 9.3
epss: "0.5%"
vendor: "NaturalIntelligence"
kev: false
exploited: false
published: "2026-02-20 21:19:27"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-22T04:50:42+02:00"
---

# CVE-2026-25896

> 9.3 CRITICAL · 🧪 PoC

## Beschreibung

fast-xml-parser allows users to validate XML, parse XML to JS object, or build XML from JS object without C/C++ based libraries and no callback. From 4.1.3to before 5.3.5, a dot (.) in a DOCTYPE entity name is treated as a regex wildcard during entity replacement, allowing an attacker to shadow built-in XML entities (<, >, &, ", ') with arbitrary values. This bypasses entity encoding and leads to XSS when parsed output is rendered. This vulnerability is fixed in 5.3.5.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Gering | warn |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- fe9a85270122036ae22637167ce38a5f71b73a5f (Commit)
- 943ef0eb1b2d3284e72dd74f44a042ee9f07026e (Commit)

## Referenzen

- <https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-m7jm-9gc2-mpf2>
- <https://github.com/NaturalIntelligence/fast-xml-parser/commit/943ef0eb1b2d3284e72dd74f44a042ee9f07026e>
- <https://github.com/NaturalIntelligence/fast-xml-parser/commit/ddcd0acf26ddd682cb0dc15a2bd6aa3b96bb1e69>
- <https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.3.5>
- <https://access.redhat.com/errata/RHSA-2026:40984>
- <https://access.redhat.com/errata/RHSA-2026:41941>
- <https://access.redhat.com/errata/RHSA-2026:41944>
- <https://access.redhat.com/errata/RHSA-2026:51349>
- <https://access.redhat.com/errata/RHSA-2026:6174>
- <https://access.redhat.com/errata/RHSA-2026:6802>
- <https://access.redhat.com/errata/RHSA-2026:7110>
- <https://access.redhat.com/errata/RHSA-2026:7128>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-25896) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_