CVE-2026-3633 Libsoup: libsoup: header and http request injection via crlf injection
Remote attackers can inject arbitrary headers and request data via CRLF injection in the method parameter, affecting applications using libsoup.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-3633?
CVE-2026-3633 is a low-severity vulnerability in Redhat Enterprise Linux, published on 17 Mar 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
A flaw was found in libsoup. A remote attacker, by controlling the method parameter of the `soup_message_new()` function, could inject arbitrary headers and additional request data. This vulnerability, known as CRLF (Carriage Return Line Feed) injection, occurs because the method value is not properly escaped during request line construction, potentially leading to HTTP request injection.
Weakness: CWE-93
Which versions are affected by CVE-2026-3633?
It affects 2 products.
Products include Gnome Libsoup, Redhat Enterprise Linux.
How do I fix CVE-2026-3633?
Apply the vendor's patch.
Is CVE-2026-3633 being exploited?
There is no known exploitation of CVE-2026-3633 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-80232, DEBIAN-CVE-2026-3633, ECHO-13f8-d7ec-bfef, GHSA-6p72-283f-crv2, UBUNTU-CVE-2026-3633.