5.9
Medium
CVE-2025-26466 Openssh: denial-of-service in openssh
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.
CVSS 3.1 detail
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitable remotely over the network, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- Interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 10 | Versions not published | |
| Red Hat Enterprise Linux 6 | Versions not published | |
| Red Hat Enterprise Linux 7 | Versions not published | |
| Red Hat Enterprise Linux 8 | Versions not published | |
| Red Hat Enterprise Linux 9 | Versions not published | |
| Red Hat OpenShift Container Platform 4 | Versions not published | |
| Red Hat In-Vehicle Operating System 1 | Versions not published | |
| SIMATIC S7-1500 CPU 1518-4 PN/DP MFP 3.1 | 3.1.0 → < 3.1.5 | 3.1.5 |
| SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP 3.1 | 3.1.0 → < 3.1.5 | 3.1.5 |
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| Product | Affected versions | Fixed in |
|---|---|---|
| SIPLUS S7-1500 CPU 1518-4 PN/DP MFP 3.1 | 3.1.0 → < 3.1.5 | 3.1.5 |
References
- RHBA-2025:6305 access.redhat.com
- RHSA-2025:6993 access.redhat.com
- access.redhat.com access.redhat.com
- RHBZ#2345043 bugzilla.redhat.com
- seclists.org seclists.org
- www.qualys.com www.qualys.com
Timeline
- Published
- Last modified
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