Vulnerability Details 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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.39
EPSS Ranking 97.1%
CVSS Severity
CVSS v3 Score 5.9
References
- https://access.redhat.com/security/cve/CVE-2025-26466
- https://bugzilla.redhat.com/show_bug.cgi?id=2345043
- https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt
- https://bugzilla.suse.com/show_bug.cgi?id=1237041
- https://security-tracker.debian.org/tracker/CVE-2025-26466
- https://security.netapp.com/advisory/ntap-20250228-0002/
- https://ubuntu.com/security/CVE-2025-26466
- https://www.openwall.com/lists/oss-security/2025/02/18/1
- https://www.openwall.com/lists/oss-security/2025/02/18/4
- https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt
Products affected by CVE-2025-26466
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cpe:2.3:a:openbsd:openssh:9.5
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cpe:2.3:a:openbsd:openssh:9.6
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cpe:2.3:a:openbsd:openssh:9.7
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cpe:2.3:a:openbsd:openssh:9.8
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cpe:2.3:a:openbsd:openssh:9.9
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cpe:2.3:o:canonical:ubuntu_linux:24.04
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cpe:2.3:o:canonical:ubuntu_linux:24.10
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cpe:2.3:o:debian:debian_linux:11.0
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cpe:2.3:o:debian:debian_linux:12.0
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cpe:2.3:o:debian:debian_linux:13.0