CVE-2026-55654 Memory corruption in Red Hat Enterprise Linux 10
Remote attackers can cause SSH service crashes via heap out-of-bounds read in GSSAPI cleanup, requiring GSSAPI and Kerberos configuration.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55654?
CVE-2026-55654 is a low-severity memory corruption vulnerability in OpenSSH, published on 23 Jun 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 OpenSSH. This vulnerability, a heap out-of-bounds read, occurs during the cleanup of GSSAPI (Generic Security Service Application Programming Interface) indicators when a trailing NULL termination is missing in the auth-indicators array. A remote attacker, under specific configurations involving GSSAPI authentication and a Kerberos environment, could exploit this to cause the SSH authentication path to crash or abort. This leads to a denial of service (DoS), impacting the availability of the SSH service.
Weakness: CWE-125
Which versions are affected by CVE-2026-55654?
It affects 3 products.
Products include OpenSSH, Redhat Enterprise Linux, Redhat Hardened Images.
How do I fix CVE-2026-55654?
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-2026-55654 being exploited?
There is no known exploitation of CVE-2026-55654 in the wild and no public exploit code.
Other vulnerabilities in OpenSSH
Sources
Also known as DEBIAN-CVE-2026-55654, GHSA-5mx2-7g4j-9m39, UBUNTU-CVE-2026-55654.