CVE-2026-44978 xrdp: Unchecked FIPS padding length in standard RDP Security causes heap out-of-bounds read in HMAC verification
An unauthenticated remote attacker can cause a denial of service via heap out-of-bounds read in xrdp when FIPS crypto is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44978?
CVE-2026-44978 is a medium-severity memory corruption vulnerability in neutrinolabs xrdp, published on 20 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
xrdp is an open source RDP server. Versions 0.10.6 and prior contain a heap out-of-bounds read vulnerability within the FIPS-specific receive paths. This vulnerability does not affect the default configuration of xrdp. The vulnerability is only exploitable when the security layer is set to security_layer=negotiate or security_layer=rdp, and the crypto level is changed to crypt_level=fips in xrdp.ini. In this specific non-default mode, the server fails to validate the FIPS padding length field, leading to a pointer underflow and a subsequent negative length calculation. An unauthenticated remote attacker can exploit this by sending a crafted FIPS-protected PDU, causing a heap out-of-bounds read that results in a process crash and denial of service (DoS). However, since xrdp forks a new process for each connection by default, an out-of-bounds read causing a process crash is unlikely to bring down the entire xrdp service. This issue has been fixed in version 0.10.6.1.
Which versions are affected by CVE-2026-44978?
It affects 1 product.
Products include Neutrinolabs Xrdp.
How do I fix CVE-2026-44978?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-44978 being exploited?
There is no known exploitation of CVE-2026-44978 in the wild and no public exploit code.
Other vulnerabilities in neutrinolabs xrdp
- CVE-2026-41252 xrdp: lib_palette_update Heap Buffer Overflow & RCE
- CVE-2026-32105 xrdp: RDP MAC signature (dataSignature) never verified on receive — integrity bypass in non-TLS mode
- CVE-2026-44178 xrdp: Channel Data Forwarding Fixed-Size Buffer Overflow
- CVE-2026-32107 xrdp: Fail-open privilege drop in sesexec — child processes may execute as root if setuid fails
- CVE-2026-33689 xrdp: Pre-authentication out-of-bounds reads in channel parsers
Sources
Also known as DEBIAN-CVE-2026-44978, GHSA-9cg5-f7m7-ppvj, UBUNTU-CVE-2026-44978.