CVE-2026-2436 Libsoup: libsoup: denial of service via use-after-free in soupserver during tls handshake
A remote attacker can crash the server by triggering a use-after-free in libsoup during TLS handshakes, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-2436?
CVE-2026-2436 is a medium-severity use after free vulnerability in Redhat Enterprise Linux, published on 26 Mar 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's SoupServer. A remote attacker could exploit a use-after-free vulnerability where the `soup_server_disconnect()` function frees connection objects prematurely, even if a TLS handshake is still pending. If the handshake completes after the connection object has been freed, a dangling pointer is accessed, leading to a server crash and a Denial of Service.
Weakness: CWE-825
Which versions are affected by CVE-2026-2436?
It affects 2 products.
Products include Gnome Libsoup, Redhat Enterprise Linux.
How do I fix CVE-2026-2436?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-2436 being exploited?
There is no known exploitation of CVE-2026-2436 in the wild and no public exploit code.
Other vulnerabilities in Redhat Enterprise Linux
- CVE-2026-102556 Libsoup: libsoup: heap buffer overflow from websocket pong signal type confusion
- CVE-2026-102557 Libsoup: libsoup: heap buffer overflow during websocket message reassembly
- CVE-2026-102558 Libsoup: libsoup: heap buffer overflow during websocket receive-buffer growth
- CVE-2026-102559 Libsoup: libsoup: heap buffer overflow during websocket client-frame masking
- CVE-2026-102560 Libsoup: libsoup: heap buffer overflow during outgoing permessage-deflate buffer growth
Sources
Also known as AZL-81519, DEBIAN-CVE-2026-2436, ECHO-defe-1984-cab6, GHSA-wpfw-5xvc-wq9w, ROOT-OS-DEBIAN-12-CVE-2026-2436, ROOT-OS-DEBIAN-13-CVE-2026-2436 and 1 more.