CVE-2025-26466
high-risk
Published 2025-02-28
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.
Do I need to act?
!
60.4% chance of exploitation in next 30 days
EPSS score — higher than 40% of all CVEs
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.9/10
Medium
NETWORK
/ HIGH complexity
Affected Products (14)
References (16)
Third Party Advisory
https://access.redhat.com/security/cve/CVE-2025-26466
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2345043
Third Party Advisory
https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt
Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1237041
Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2025-26466
Third Party Advisory
https://security.netapp.com/advisory/ntap-20250228-0002/
Third Party Advisory
https://ubuntu.com/security/CVE-2025-26466
Third Party Advisory
https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt
55
/ 100
high-risk
Severity
18/34 · Moderate
Exploitability
19/34 · Moderate
Exposure
18/34 · Moderate