---
cve: "CVE-2026-56412"
severity: "MEDIUM"
cvss: 4.9
epss: "19%"
vendor: "libexpat project"
kev: false
exploited: false
published: "2026-06-21 17:16:44"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-19T14:56:51+02:00"
---

# CVE-2026-56412

> 4.9 MEDIUM · 🧪 PoC

## Beschreibung

libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- c61098da494eea1cbd091118118dcee417faacea (Commit)

## Referenzen

- <https://github.com/libexpat/libexpat/pull/1278>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-56412) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_