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.
References
| Link | Resource |
|---|---|
| https://access.redhat.com/security/cve/CVE-2025-26466 | Third Party Advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=2345043 | Issue Tracking |
| https://seclists.org/oss-sec/2025/q1/144 | |
| https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt | Third Party Advisory |
| http://seclists.org/fulldisclosure/2025/Feb/18 | |
| http://seclists.org/fulldisclosure/2025/May/7 | |
| http://seclists.org/fulldisclosure/2025/May/8 | |
| 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.openwall.com/lists/oss-security/2025/02/18/1 | Mailing List Third Party Advisory |
| https://www.openwall.com/lists/oss-security/2025/02/18/4 | Mailing List Third Party Advisory |
| https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt | Third Party Advisory |
Configurations
Configuration 1 (hide)
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Configuration 2 (hide)
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Configuration 3 (hide)
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History
03 Nov 2025, 22:18
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Information
Published : 2025-02-28 22:15
Updated : 2025-11-03 22:18
NVD link : CVE-2025-26466
Mitre link : CVE-2025-26466
CVE.ORG link : CVE-2025-26466
JSON object : View
Products Affected
openbsd
- openssh
canonical
- ubuntu_linux
debian
- debian_linux
CWE
CWE-770
Allocation of Resources Without Limits or Throttling