Severity by source
Sources disagree (Low–High)AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Requires the non-default GSSAPIAuthentication feature enabled (AC:H); unauthenticated network reachable (PR:N/AV:N); partial resource-consumption DoS per SSVC so availability-only and A:L, no C/I impact.
AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.
CVSS VectorNVD
Lifecycle Timeline
7DescriptionNVD
sshd in OpenSSH before 10.4 allows remote attackers to cause a denial of service (resource consumption from excessive authentication attempts) because MaxAuthTries was mishandled for GSSAPIAuthentication.
AnalysisAI
Denial of service in OpenSSH sshd before 10.4 lets remote unauthenticated attackers exhaust server resources by driving excessive authentication attempts, because the MaxAuthTries cap was not correctly enforced for the GSSAPIAuthentication path. Only deployments that have enabled GSSAPI-based authentication are exposed, and there is no public exploit identified at time of analysis. EPSS is low (0.34%, 26th percentile) and CISA SSVC records no observed exploitation, so this is a real but non-urgent availability issue rather than a code-execution threat.
Technical ContextAI
The affected component is sshd, the OpenSSH server daemon (cpe:2.3:a:openbsd:openssh). OpenSSH normally bounds the number of failed authentication attempts per connection via the MaxAuthTries directive, forcing a disconnect once the limit is reached. The flaw is a CWE-770 (Allocation of Resources Without Limits or Throttling) issue: in the GSSAPIAuthentication code path the MaxAuthTries counter was mishandled, so an attacker could keep submitting authentication attempts beyond the intended ceiling. Each attempt consumes CPU, memory and connection-handling resources, and GSSAPI/Kerberos negotiation is comparatively expensive, so repeated attempts can degrade or exhaust server capacity. GSSAPIAuthentication is disabled by default in stock OpenSSH and is typically enabled only in Kerberos/Active Directory integrated environments.
RemediationAI
Vendor-released patch: OpenSSH 10.4 (portable 10.4p1) - upgrade sshd to 10.4/10.4p1 or later, or apply the fixed package from your distribution once it incorporates the upstream release (https://www.openssh.org/releasenotes.html#10.4p1). Where immediate patching is not possible, the most direct compensating control is to disable the vulnerable feature by setting 'GSSAPIAuthentication no' in sshd_config and restarting sshd; the trade-off is that Kerberos/GSSAPI single sign-on will stop working, so this is only safe in environments that do not rely on it. Additionally, restrict network reachability of TCP/22 to trusted management networks or via firewall/VPN to limit who can initiate authentication floods, and apply rate-limiting/connection throttling at the network edge (e.g. per-source connection limits) to blunt resource-exhaustion attempts; these do not fix the underlying counter mishandling but reduce exposure. Consult the oss-security announcement at https://www.openwall.com/lists/oss-security/2026/07/06/5 for details.
GNU Bash through 4.3 processes trailing strings after function definitions in the values of environment variables, which
GNU Bash through 4.3 bash43-026 does not properly parse function definitions in the values of environment variables, whi
GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed function definitions in the values of
freeSSHd.exe in freeSSHd through 1.2.6 allows remote attackers to bypass authentication via a crafted session, as demons
GNU Bash through 4.3 bash43-026 does not properly parse function definitions in the values of environment variables, whi
OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling. Rated medium se
sshd in OpenSSH before 7.3, when SHA256 or SHA512 are used for user password hashing, uses BLOWFISH hashing on a static
The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processin
The auth_password function in auth-passwd.c in sshd in OpenSSH before 7.3 does not limit password lengths for password a
Remote code execution in OpenSSH's sshd server (regression of CVE-2006-5051) allows unauthenticated remote attackers to
The SSH USERAUTH CHANGE REQUEST feature in SSH Tectia Server 6.0.4 through 6.0.20, 6.1.0 through 6.1.12, 6.2.0 through 6
A vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. Rated medium severity (CVSS 6.8), this
Same technique Denial Of Service
View allVendor StatusVendor
SUSE
Severity: Low| Product | Status |
|---|---|
| SLES15-SP5-CHOST-BYOS-SAP-CCloud | Affected |
| SLES15-SP6-CHOST-BYOS | Affected |
| SLES15-SP6-CHOST-BYOS-Aliyun | Affected |
| SLES15-SP6-CHOST-BYOS-Azure | Affected |
| SLES15-SP6-CHOST-BYOS-EC2 | Affected |
| SLES15-SP6-CHOST-BYOS-GCE | Affected |
| SLES15-SP6-CHOST-BYOS-GDC | Affected |
| SLES15-SP6-CHOST-BYOS-SAP-CCloud | Affected |
| SLES15-SP7-CHOST-BYOS-Aliyun | Affected |
| SLES15-SP7-CHOST-BYOS-Azure | Affected |
| SLES15-SP7-CHOST-BYOS-EC2 | Affected |
| SLES15-SP7-CHOST-BYOS-GCE | Affected |
| SLES15-SP7-CHOST-BYOS-GDC | Affected |
| SLES15-SP7-CHOST-BYOS-SAP-CCloud | Affected |
| SUSE Linux Enterprise Desktop 15 SP7 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Affected |
| SUSE Linux Enterprise Micro 5.3 | Affected |
| SUSE Linux Enterprise Micro 5.4 | Affected |
| SUSE Linux Enterprise Micro 5.5 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Desktop Applications 15 SP7 | Affected |
| SUSE Linux Enterprise Server 15 SP7 | Affected |
| SUSE Linux Enterprise Server 16.0 | Affected |
| SUSE Linux Enterprise Server 16.1 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Affected |
| SUSE Linux Micro 6.0 | Affected |
| SUSE Linux Micro 6.1 | Affected |
| SUSE Linux Micro 6.2 | Affected |
| openSUSE Leap 16.0 | Affected |
| SLES15-SP3-CHOST-BYOS-Aliyun | Affected |
| SLES15-SP3-CHOST-BYOS-Azure | Affected |
| SLES15-SP3-CHOST-BYOS-EC2 | Affected |
| SLES15-SP3-CHOST-BYOS-GCE | Affected |
| SLES15-SP3-CHOST-BYOS-SAP-CCloud | Affected |
| SLES15-SP4-CHOST-BYOS | Affected |
| SLES15-SP4-CHOST-BYOS-Aliyun | Affected |
| SLES15-SP4-CHOST-BYOS-Azure | Affected |
| SLES15-SP4-CHOST-BYOS-EC2 | Affected |
| SLES15-SP4-CHOST-BYOS-GCE | Affected |
| SLES15-SP4-CHOST-BYOS-SAP-CCloud | Affected |
| SLES15-SP5-CHOST-BYOS-Aliyun | Affected |
| SLES15-SP5-CHOST-BYOS-Azure | Affected |
| SLES15-SP5-CHOST-BYOS-EC2 | Affected |
| SLES15-SP5-CHOST-BYOS-GCE | Affected |
| SLES15-SP5-CHOST-BYOS-GDC | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | Affected |
| SUSE Linux Enterprise Server 12 SP5 | Affected |
| SUSE Linux Enterprise Server 12 SP5 | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | Affected |
| SUSE Linux Enterprise Server 15 SP4 | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP5 | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP6 | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | Affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Affected |
| SUSE Manager Proxy 4.3 | Affected |
| SUSE Manager Proxy LTS 4.3 | Affected |
| SUSE Manager Retail Branch Server 4.3 | Affected |
| SUSE Manager Retail Branch Server LTS 4.3 | Affected |
| SUSE Manager Server 4.3 | Affected |
| SUSE Manager Server LTS 4.3 | Affected |
| SUSE CaaS Platform 3.0 | Affected |
| SUSE CaaS Platform 4.0 | Affected |
| SUSE Enterprise Storage 6 | Affected |
| SUSE Enterprise Storage 7 | Affected |
| SUSE Enterprise Storage 7.1 | Affected |
| SUSE Linux Enterprise Desktop 11 SP4 | Affected |
| SUSE Linux Enterprise Desktop 12 SP2 | Affected |
| SUSE Linux Enterprise Desktop 12 SP3 | Affected |
| SUSE Linux Enterprise Desktop 12 SP4 | Affected |
| SUSE Linux Enterprise Desktop 15 SP1 | Affected |
| SUSE Linux Enterprise Desktop 15 SP2 | Affected |
| SUSE Linux Enterprise Desktop 15 SP3 | Affected |
| SUSE Linux Enterprise Desktop 15 SP4 | Affected |
| SUSE Linux Enterprise Desktop 15 SP5 | Affected |
| SUSE Linux Enterprise Desktop 15 SP6 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | Affected |
| SUSE Linux Enterprise Micro 5.0 | Affected |
| SUSE Linux Enterprise Micro 5.1 | Affected |
| SUSE Linux Enterprise Micro 5.2 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP1 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP2 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP3 | Affected |
| SUSE Linux Enterprise Point of Sale 12 SP2-CLIENT | Affected |
| SUSE Linux Enterprise Real Time 15 SP2 | Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | Affected |
| SUSE Linux Enterprise Server 11 SP4 | Affected |
| SUSE Linux Enterprise Server 11 SP4-LTSS | Affected |
| SUSE Linux Enterprise Server 12 SP2 | Affected |
| SUSE Linux Enterprise Server 12 SP2-BCL | Affected |
| SUSE Linux Enterprise Server 12 SP2-ESPOS | Affected |
| SUSE Linux Enterprise Server 12 SP2-LTSS | Affected |
| SUSE Linux Enterprise Server 12 SP3 | Affected |
| SUSE Linux Enterprise Server 12 SP3-BCL | Affected |
| SUSE Linux Enterprise Server 12 SP3-ESPOS | Affected |
| SUSE Linux Enterprise Server 12 SP3-LTSS | Affected |
| SUSE Linux Enterprise Server 12 SP4 | Affected |
| SUSE Linux Enterprise Server 15 SP1 | Affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP2 | Affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP3 | Affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise Server for Raspberry Pi 12 SP2 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP2 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP3 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Affected |
| SUSE Manager Proxy 4.0 | Affected |
| SUSE Manager Proxy 4.1 | Affected |
| SUSE Manager Proxy 4.2 | Affected |
| SUSE Manager Retail Branch Server 4.0 | Affected |
| SUSE Manager Retail Branch Server 4.1 | Affected |
| SUSE Manager Retail Branch Server 4.2 | Affected |
| SUSE Manager Server 4.0 | Affected |
| SUSE Manager Server 4.1 | Affected |
| SUSE Manager Server 4.2 | Affected |
| SUSE OpenStack Cloud 7 | Affected |
| SUSE OpenStack Cloud 8 | Affected |
| SUSE OpenStack Cloud Crowbar 8 | Affected |
| openSUSE Leap 15.3 | Affected |
| openSUSE Leap 15.4 | Affected |
| openSUSE Leap 15.5 | Affected |
| openSUSE Leap 15.6 | Affected |
| openSUSE Leap Micro 5.2 | Affected |
| openSUSE Leap Micro 5.3 | Affected |
| openSUSE Leap Micro 5.4 | Affected |
| openSUSE Leap Micro 5.5 | Affected |
| SLES-CHOST-BYOS-Aliyun | Affected |
| SLES-CHOST-BYOS-Azure | Affected |
| SLES-CHOST-BYOS-EC2 | Affected |
| SLES-CHOST-BYOS-GCE | Affected |
| SLES-CHOST-BYOS-GDC | Affected |
| SLES-CHOST-BYOS-SAP-CCloud | Affected |
| kiwi-templates-Minimal kiwi-templates-Minimal-Cloud-sap kiwi-templates-Minimal-MS-HyperV-sap kiwi-templates-Minimal-VMware-sap kiwi-templates-Minimal-kvm-and-xen-sap ses/7.1/cephcsi/cephcsi ses/7.1/rook/ceph ses/7/ceph/ceph ses/7/cephcsi/cephcsi ses/7/rook/ceph suse/hpc/warewulf4-x86_64/sle-hpc-node suse/manager/4.3/proxy-ssh suse/manager/5.0/x86_64/proxy-ssh suse/manager/5.0/x86_64/server suse/multi-linux-manager/5.1/x86_64/proxy-ssh suse/multi-linux-manager/5.1/x86_64/server suse/multi-linux-manager/5.2/x86_64/proxy-ssh suse/multi-linux-manager/5.2/x86_64/server suse/sle-micro-rancher/5.2 suse/sle-micro-rancher/5.3 suse/sle-micro-rancher/5.4 suse/sle-micro/5.5 trento/trento-runner | Affected |
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-42143
GHSA-76jm-35gr-hwcm