OpenSSH GSSAPI out-of-bounds

Summaryinfo

A vulnerability categorized as problematic has been discovered in OpenSSH. Affected is an unknown function of the component GSSAPI. Such manipulation leads to out-of-bounds. This vulnerability is referenced as CVE-2026-55654. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in OpenSSH (affected version unknown). Affected by this issue is an unknown functionality of the component GSSAPI. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is availability. CVE summarizes:

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.

The advisory is shared for download at access.redhat.com. This vulnerability is handled as CVE-2026-55654 since 06/17/2026. The exploitation is known to be difficult. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 06/23/2026).

The vulnerability scanner Nessus provides a plugin with the ID 322154 (Linux Distros Unpatched Vulnerability : CVE-2026-55654), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Tenable (322154), EUVD (EUVD-2026-38414) and CERT Bund (WID-SEC-2026-2039). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Open Source OpenSSH

Productinfo

Type

• Connectivity Software

Name

• OpenSSH

License

• open-source

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion