---
title: "CVE-2026-102558: libsoup - Buffer Overflow"
description: "libsoup contains a heap buffer overflow caused by an integer wrap in SoupWebsocketConnection when max-incoming-payload-size is unlimited (0), letting attackers cause memory corruption, exploit requires attacker to send crafted websocket frames."
url: https://panop.io/threat-heartbeat/CVE-2026-102558/
---

# CVE-2026-102558 libsoup - Buffer Overflow

libsoup contains a heap buffer overflow caused by an integer wrap in SoupWebsocketConnection when max-incoming-payload-size is unlimited (0), letting attackers cause memory corruption, exploit requires attacker to send crafted websocket frames.

CVSS base score 8.6 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.30% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-102558)

## Details

Type

Buffer Overflow

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-125](https://cwe.mitre.org/data/definitions/125.html)

## Vendor fix

Update to the latest version with the fix applied.

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-2026-102558](https://nvd.nist.gov/vuln/detail/CVE-2026-102558)
- [https://access.redhat.com/security/cve/CVE-2026-102558](https://access.redhat.com/security/cve/CVE-2026-102558)
- [https://bugzilla.redhat.com/show\_bug.cgi?id=2543274](https://bugzilla.redhat.com/show_bug.cgi?id=2543274)
- [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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