CVEvulnerability
CVE-2025-26466
5.9 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2025-02-28
- Last modified
- 2026-10-21
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 5.9 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- CVSS 3.1 ([email protected])
- 5.9 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-770
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.
Affected configurations
• openbsd openssh 9.5
• openbsd openssh 9.6
• openbsd openssh 9.7
• openbsd openssh 9.8
• openbsd openssh 9.9
• canonical ubuntu linux 24.04
• canonical ubuntu linux 24.10
• debian debian linux 11.0
• debian debian linux 12.0
• debian debian linux 13.0
Related
Weakness · CWE (1)
- CWE-770 Allocation of Resources Without Limits or Throttling weakness
References
- https://access.redhat.com/errata/RHBA-2025:6305 access.redhat.com
- https://access.redhat.com/errata/RHSA-2025:6993 access.redhat.com
- 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 seclists.org
- https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt Third Party Advisory
- http://seclists.org/fulldisclosure/2025/Feb/18 seclists.org
- http://seclists.org/fulldisclosure/2025/May/7 seclists.org
- http://seclists.org/fulldisclosure/2025/May/8 seclists.org
- 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.vicarius.io/vsociety/posts/cve-2025-26466-detection-script-memory-consumption-vulnerability-in-openssh www.vicarius.io
- https://www.vicarius.io/vsociety/posts/cve-2025-26466-mitigation-script-memory-consumption-vulnerability-in-openssh www.vicarius.io
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html cert-portal.siemens.com
- https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt Third Party Advisory