CVE-2026-12478

Severity CVSS v4.0:

Pending analysis

Type:

CWE-125 Out-of-bounds Read

Publication date:

14/07/2026

Last modified:

14/07/2026

Description

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L CVSS v3.1 Severity and Metrics:

Base Score: 4.80 MEDIUM
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): Low
Integrity (I): None
Availability (A): Low

Base Score 3.x

4.80

Severity 3.x

MEDIUM

CVE-2026-12478

Description

Impact

References to Advisories, Solutions, and Tools