Out-of-bounds Read Affecting libsoup3 package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.24% (14th percentile)

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  • Snyk IDSNYK-UBUNTU2610-LIBSOUP3-21220411
  • published22 Oct 2026
  • disclosed14 Jul 2026

Introduced: 14 Jul 2026

CVE-2026-12478  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

There is no fixed version for Ubuntu:26.10 libsoup3.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libsoup3 package and not the libsoup3 package as distributed by Ubuntu. See How to fix? for Ubuntu:26.10 relevant fixed versions and status.

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 Base Scores

version 3.1