---
id: CVE-2026-102556
title: A flaw was found in libsoup
summary: >-
  A flaw was found in libsoup. When handling an incoming WebSocket Pong frame,
  SoupWebsocketConnection emitted the ::pong signal with a GByteArray pointer
  even though the signal is declared to pass a GBytes. Applications connecting a
  handl…
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-843
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: '2026-09-29T17:17:06.460'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102556'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-102556'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2543229'
    label: secalert@redhat.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-29T17:23:43.057392Z'
ingestedAt: '2026-09-29T16:39:33.275Z'
---

## Overview

A flaw was found in libsoup. When handling an incoming WebSocket Pong frame, SoupWebsocketConnection emitted the ::pong signal with a GByteArray pointer even though the signal is declared to pass a GBytes. Applications connecting a handler that follows the documented GBytes API can trigger heap corruption or a crash upon receiving a crafted Pong.

## Remediation

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