---
id: CVE-2026-102557
title: A flaw was found in libsoup
summary: >-
  A flaw was found in libsoup. When reassembling fragmented WebSocket messages
  into a GByteArray, libsoup did not adequately cap total message size against
  the limits of the underlying buffer type. A remote peer could send fragments
  that c…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H'
cwe:
  - CWE-125
vendor: Red Hat
product: libsoup3
affected:
  - libsoup3 (all versions)
  - libsoup
  - libsoup (all versions)
  - libsoup (all versions)
  - libsoup (all versions)
published: '2026-09-29'
updated: '2026-09-29'
sourceUpdated: '2026-09-29T17:17:06.600'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102557'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-102557'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2543231'
    label: secalert@redhat.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-29T16:39:33.276Z'
---

## Overview

A flaw was found in libsoup. When reassembling fragmented WebSocket messages into a GByteArray, libsoup did not adequately cap total message size against the limits of the underlying buffer type. A remote peer could send fragments that caused size truncation while the implementation still used the full length, leading to heap corruption or a crash.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.