CVE-2026-102560 Libsoup: libsoup: heap buffer overflow during outgoing permessage-deflate buffer growth

High 8.6 Published 29 Sep 2026 Updated 22 Oct 2026

Heap buffer overflow in libsoup during WebSocket compression allows attackers to execute code or cause denial of service via large messages.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-102560?

CVE-2026-102560 is a high-severity memory corruption vulnerability in Redhat Enterprise Linux, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A flaw was found in libsoup. When the permessage-deflate WebSocket extension compresses a very large outgoing message, truncated size calculations used for GByteArray growth could wrap, causing zlib to write past the allocated buffer and resulting in a heap buffer overflow.

Weakness: CWE-125

Which versions are affected by CVE-2026-102560?

It affects 2 products.

Products include Gnome Libsoup, Redhat Enterprise Linux.

How do I fix CVE-2026-102560?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-102560 being exploited?

There is no known exploitation of CVE-2026-102560 in the wild and no public exploit code.

All Redhat Enterprise Linux vulnerabilities

Sources

Also known as AZL-105540, DEBIAN-CVE-2026-102560, ECHO-4ddc-e650-11be, GHSA-9v45-6jmj-gmwr, UBUNTU-CVE-2026-102560.