Out-of-bounds Read in OpenBSD OpenSSH
CVE-2026-55654
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.007 (49.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.002
Affected products
- OpenBSD OpenSSH
- Red Hat Enterprise Linux 10 — versions 0:9.9p1-25.el10_2
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9 — versions 0:9.9p1-9.el9_8
- Red Hat Hardened Images — versions 10.3p1-6.hum1
- Red Hat Openshift Container Platform 4
- Red Hat Update Infrastructure 5 — versions 1786435483, 1786533529
- Red Hat Enterprise Linux — versions 6.0, 7.0, 8.0
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-55654 (vdb-entry, Vendor Advisory)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Exploit, Issue Tracking, Vendor Advisory)
- access.redhat.com/errata/RHSA-2026:36759 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:47756 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:47757 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:54387 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:58981 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-55654?
- CVE-2026-55654 is a low-severity vulnerability in OpenBSD OpenSSH, classified under Out-of-bounds Read. CVSS score: 3.7/10. Published 2026-06-23.
- How severe is CVE-2026-55654?
- Low severity. CVSS v3 base score is 3.7 out of 10.