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CVE-2025-26466

Openssh: denial-of-service in openssh

Published: Feb 28, 2025Updated: Feb 10, 2026 Sources: CVE List NVD BDU csafCWE-770
NVD MITRE
5.9CVSSMEDIUM
EPSS Score
38.5%
Top 1.6%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.

CVSS Vector Breakdown

AV:NAC:HPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-770

Affected Products

Red Hat Enterprise Linux 10Red Hat
On-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 6Red Hat
On-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 7Red Hat
On-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8Red Hat
On-premOS
Operating Systems / linux-distro
red hatcommercialUSOperating Systemsaka red hat
and 17 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available
Workaround Available

MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://access.redhat.com/security/cve/CVE-2025-26466
access.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2345043
bugzilla.redhat.com
https://seclists.org/oss-sec/2025/q1/144
seclists.org
and 27 more references View all →

Timeline

Published
Feb 28, 2025
Last Updated
Feb 10, 2026

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