CVE-2025-26466
MEDIUMCVSS v3
5.9
MEDIUM
EPSS Score
42.5%
exploit probability
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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.
Technical Details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2/28/2025
- Last Modified
- 6/30/2026
Frequently Asked Questions
What is CVE-2025-26466?
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.
Is CVE-2025-26466 actively exploited?
Active exploitation of CVE-2025-26466 has not been confirmed. The EPSS score is 42.5%, indicating the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2025-26466?
CVE-2025-26466 has a CVSS v3 base score of 5.9 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
Is CVE-2025-26466 affecting your environment?
Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.