UBUNTU-CVE-2025-26466

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Source
https://ubuntu.com/security/CVE-2025-26466
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-26466.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2025-26466
Upstream
Downstream
Related
Published
2025-02-18T00:00:00Z
Modified
2025-09-08T17:08:12Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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

Affected packages

Ubuntu:24.04:LTS / openssh

Package

Name
openssh
Purl
pkg:deb/ubuntu/openssh@1:9.6p1-3ubuntu13.8?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1:9.6p1-3ubuntu13.8

Affected versions

1:9.*

1:9.3p1-1ubuntu3
1:9.4p1-1ubuntu1
1:9.6p1-3ubuntu1
1:9.6p1-3ubuntu2
1:9.6p1-3ubuntu11
1:9.6p1-3ubuntu12
1:9.6p1-3ubuntu13
1:9.6p1-3ubuntu13.3
1:9.6p1-3ubuntu13.4
1:9.6p1-3ubuntu13.5
1:9.6p1-3ubuntu13.7

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "openssh-client",
            "binary_version": "1:9.6p1-3ubuntu13.8"
        },
        {
            "binary_name": "openssh-server",
            "binary_version": "1:9.6p1-3ubuntu13.8"
        },
        {
            "binary_name": "openssh-sftp-server",
            "binary_version": "1:9.6p1-3ubuntu13.8"
        },
        {
            "binary_name": "openssh-tests",
            "binary_version": "1:9.6p1-3ubuntu13.8"
        },
        {
            "binary_name": "ssh",
            "binary_version": "1:9.6p1-3ubuntu13.8"
        },
        {
            "binary_name": "ssh-askpass-gnome",
            "binary_version": "1:9.6p1-3ubuntu13.8"
        }
    ],
    "availability": "No subscription required"
}