---
title: "CVE-2026-102556: libsoup - Denial of Service"
description: "libsoup contains a heap corruption vulnerability caused by emitting the ::pong signal with a GByteArray pointer instead of GBytes in SoupWebsocketConnection, letting attackers cause crashes or memory corruption via crafted Pong frames, exploit requires crafted WebSocket Pong frames."
url: https://panop.io/threat-heartbeat/CVE-2026-102556/
---

# CVE-2026-102556 libsoup - Denial of Service

libsoup contains a heap corruption vulnerability caused by emitting the ::pong signal with a GByteArray pointer instead of GBytes in SoupWebsocketConnection, letting attackers cause crashes or memory corruption via crafted Pong frames, exploit requires crafted WebSocket Pong frames.

CVSS base score 8.6 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.22% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-102556)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

Published

29 September 2026

Updated

15 October 2026

Weakness

[CWE-843](https://cwe.mitre.org/data/definitions/843.html)

## Vendor fix

Update to the latest version of libsoup containing the fix.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-102556](https://nvd.nist.gov/vuln/detail/CVE-2026-102556)
- [https://access.redhat.com/security/cve/CVE-2026-102556](https://access.redhat.com/security/cve/CVE-2026-102556)
- [https://bugzilla.redhat.com/show\_bug.cgi?id=2543229](https://bugzilla.redhat.com/show_bug.cgi?id=2543229)
- [https://access.redhat.com/errata/RHSA-2026:83384](https://access.redhat.com/errata/RHSA-2026:83384)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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