---
cve: "CVE-2026-12478"
severity: "MEDIUM"
cvss: 4.8
epss: "0.4%"
vendor: "Generic Security"
kev: false
exploited: false
published: "2026-07-14 10:16:30"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T05:37:01+02:00"
---

# CVE-2026-12478

> 4.8 MEDIUM

## Beschreibung

The fix for CVE-2026-0716 (commit 6ff7ef0, libsoup 3.6.6) placed the integer overflow guard inside the if (masked) block, leaving unmasked server-to-client frames unprotected. A malicious WebSocket server can send a crafted unmasked frame with a payload length near UINT64_MAX to trigger an OOB read in a libsoup-based client when max_incoming_payload_size is set to 0.

## CVSS-Vektor

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

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

## Referenzen

- <https://access.redhat.com/security/cve/CVE-2026-12478>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2489655>
- <https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/518>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-12478) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_