---
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: gnome
product: libsoup
affected:
  - libsoup < 3.7.3
  - enterprise_linux = 7.0
  - enterprise_linux = 8.0
  - enterprise_linux = 9.0
  - enterprise_linux = 10.0
patched:
  - libsoup 3.7.3
published: '2026-09-29'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T17:17:09.380'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102557'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:83384'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:83618'
    label: secalert@redhat.com
  - 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
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-102557.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-102557'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102557'
  - url: 'https://access.redhat.com/errata/RHSA-2026:84586'
    label: 'RHSA-2026:84586'
  - url: 'https://access.redhat.com/errata/RHSA-2026:92347'
    label: 'RHSA-2026:92347'
  - url: 'https://access.redhat.com/errata/RHSA-2026:93445'
    label: 'RHSA-2026:93445'
  - url: 'https://access.redhat.com/errata/RHSA-2026:93446'
    label: 'RHSA-2026:93446'
  - url: 'https://access.redhat.com/errata/RHSA-2026:93447'
    label: 'RHSA-2026:93447'
  - url: 'https://access.redhat.com/errata/RHSA-2026:93465'
    label: 'RHSA-2026:93465'
  - url: 'https://access.redhat.com/errata/RHSA-2026:93466'
    label: 'RHSA-2026:93466'
  - url: 'https://access.redhat.com/errata/RHSA-2026:93583'
    label: 'RHSA-2026:93583'
  - url: 'https://access.redhat.com/errata/RHSA-2026:93716'
    label: 'RHSA-2026:93716'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-30T19:40:49.899291Z'
epss: 0.00467
epssPercentile: 0.40537
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.

## Affected

- `libsoup < 3.7.3`
- `enterprise_linux = 7.0`
- `enterprise_linux = 8.0`
- `enterprise_linux = 9.0`
- `enterprise_linux = 10.0`

## Remediation

Upgrade past the affected range:

- `libsoup 3.7.3`

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7 · updated 2026-10-19 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-102557.json)
- **RHSA-2026:83618** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-10-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:83618)
- **RHSA-2026:83384** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-10-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:83384)
- **RHSA-2026:84586** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux BaseOS (v. 8) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:84586)