---
cve: "CVE-2026-43820"
severity: "HIGH"
cvss: 7.7
epss: "8%"
vendor: "Apple"
kev: false
exploited: false
published: "2026-07-23 15:17:05"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-11T13:01:36+02:00"
---

# CVE-2026-43820

> 7.7 HIGH · 🧪 PoC

## Beschreibung

NIOSSLCertificate._subjectAlternativeNames provides access to the raw bytes for a cert's SANs. NIOSSL provides access to a buffer assumed to be backed by an ASN1_STRING, but not all SANs are backed by ASN1_STRING, so accessing the buffer for such a type can lead to out-of-bounds memory access. This vulnerability is addressed in swift-nio-ssl version 2.37.2.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- d930168b86f46ca51a4bc09c5ca45c1833db8067 (Commit)

## Referenzen

- <https://github.com/apple/swift-nio-ssl/security/advisories/GHSA-xfxg-9975-pc2j>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-43820) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_